Ford 351 with PCM manifold heating up while idling
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=20875
Printed Date: January-15-2025 at 1:00pm
Topic: Ford 351 with PCM manifold heating up while idling
Posted By: ZenZeus
Subject: Ford 351 with PCM manifold heating up while idling
Date Posted: March-10-2011 at 2:33am
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Hi all,
Well I can't wait to show you my 6 year restoration project on my 77' ski nautique. Will post pics in week or 2. Before I get to problem - The long block, intake and all engine components are brand new. the boat was just started for the first time last weekend. I put a FWC system on it. New hoses - everything. (I bought these 96' PCM manifolds and risers used - looked good from surface) I am using a proflo system to flush boat on trailer. Plenty of water is flowing out the flappers equally on both sides. Raw water pump is new with new impeller. The motor starts up fine. The motor idles fine. The intake, heads, valves and riser elbows are is cool to touch. The heat exchange is cool and warm right at thermo - like it should be. After about 3-5 minutes I notice steam coming from the driver's side manifold. Really hot to the touch along the bottom especially- although the elbow and riser is not hot. The other side is cool. Both heads are warm to touch and feel to be the same temp. Nothing alarming there. I need some help. I don't want to jeapordize the new motor. I read a few things on various forums. here are some of those: - gasket on riser could be facing wrong way - no, mine has tab to rear. - maybe my engine doesn't reach operating temperature when in idle. It could be that when your thermostat is closed only 1 side of the exhaust get enough water (the cold side) and the other side get less - lots of water pouring out back on both sides so thinking something else. - a guy mentioned that could be just hot at idle and higher revs will provide more flow pressure and work just fine - I am not comfortable with that. - There is also a flapper on the inside of some of the exhaust manifolds that can stick in the closed position and cause this problem - I am thinking this may be the cause. How do I know if manifold is bad? Can I run some test on the manifold somehow somehow? Problem 2: Not sure about my temp sending unit (new too) / temp gauge - . When I turn the key from a cold start the temp meter reads 190-200. As it idles the temp creeps up to 240 however the motor, block, intake, heat exchanger, valves and heads are barley warm not even hot - So Im think something is up with temp unit or gauge. I am not sure how a cold motor can read 200 at start up. Anyone got any suggestions for me? I sure could use some. Thank you very much, Mark |
Replies:
Posted By: ZenZeus
Date Posted: March-10-2011 at 2:34am
| Oh, its a ford 351 escort reverse rotation |
Posted By: 8122pbrainard
Date Posted: March-10-2011 at 8:59am
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Mark,
Welcome to CCfan. With all the skilled tech help here, I know we can help. Heat exchanger? Do you have a fresh water cooling system? When you got the new temp sender, did you match the Ohm range to the old gauge? Post some pictures showing the routing of the cooling system (hoses). Make sure you get the pictures posted!!!  ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: eric lavine
Date Posted: March-10-2011 at 9:45am
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Pete, maybe he is refering to his trans cooler?
pictures are important ------------- "the things you own will start to own you" |
Posted By: eric lavine
Date Posted: March-10-2011 at 9:48am
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what is the condition of your RWP, it could be pulling air thru the seal or weep hole. airiated water completely looses its ability to transfer heat ------------- "the things you own will start to own you" |
Posted By: ZenZeus
Date Posted: March-10-2011 at 2:15pm
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Thank you guys for responding.
FWC system - yes from monitor. brand new. All new hoses throughout motor RWP is rebuilt with new impeller. Upon speaking with Ski DIM, rich said I had an automotive temp sending unit. I just checked out the woring by grounding it and it pegged the gauge to hot. Getting new one today. Rich also said the that the heat on manifold on driver side will get hotter than other side - a tad more with an FWC. Does this sound correct you guys out there? I am going to replace sending unit and see if I can get temp to reflect correctly, then keep a close eye on manifold heat. I will post pics later on today. again thanks, and I am so excited to get this baby in the water. |
Posted By: 8122pbrainard
Date Posted: March-10-2011 at 4:26pm
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Mark,
I'm glad to hear you're making some head way, getting answers and things are looking normal. I wouldn't worry about the steam out the tail end. Depending on the dew point you will get it. Since the starboard side is running hotter, it most likely got to the point where you got steam. BTW, regarding the temp sender problem, don't shop at Autozone!!   ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: ZenZeus
Date Posted: March-10-2011 at 4:43pm
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Thanks Pete,
BTW love the ski tique and the year 77' :) The steam is rising off the manifold area not the tail (I have cover off motor). I think it maybe from various oils and residues on manifold from building engine and so forth. The riser is cool. the motor is warm. I think once I have a chance to run the boat in open water the increased flow pressure will cool it down a little. I will shoot video of steam and post it soon. Thanks again bud. |
Posted By: eric lavine
Date Posted: March-10-2011 at 8:41pm
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water does take its easier path and yes at times will favor one side more than the other, how hot is hot? if you dont have access to a digital thermometer, simply put a heat thermometer on there and get some temp readings, they are exhaust manifolds and will get hot. one good way to gauge if you think they are getting excessively hot is to put some water on the hot manifold and if it instantly boils then you know its past 212 degrees. ------------- "the things you own will start to own you" |
Posted By: ZenZeus
Date Posted: March-10-2011 at 11:29pm
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Thanks Eric,
I will use that test and get back to this post. |
Posted By: Keeganino
Date Posted: March-11-2011 at 1:07am
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What is the highest "safe" temp you can run at? I noticed my temps creeping up close to 190 at the end of the season. I am getting ready to put in a new circulation pump though. Came yesterday in the mail. Good shape and the internals look brand new. Hope that cools her down a few degrees. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: OverMyHead
Date Posted: March-11-2011 at 7:05am
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I dont know the max but that is getting hot, water boils at 212 degrees. I have a 145 degree thermostat, usually run at 150 to 155. Hopefully the pump resolves the problem. ------------- For thousands of years men have felt the irresistible urge to go to sea, and many of them died. Things got better after they invented boats. 1987 Ski Nautique |
Posted By: 8122pbrainard
Date Posted: March-11-2011 at 8:55am
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Keegan and Dave,
You really do not want to get the engine close to boiling unless you have a FWC system. If it boils, the steam/air pockets don't tranfer the heat. On a FWC closed system like a car, the pressurization keeps the boiling from happening and the reason they can run pretty hot. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Keeganino
Date Posted: March-11-2011 at 2:28pm
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That makes sense. I wondered why a car could run so much hotter. I hope the new circulation pump brings the temp down. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: TRBenj
Date Posted: March-11-2011 at 2:40pm
Not that a circ pump failure couldnt cause you to overheat, but that sure doesnt seem to be a common cause on these engines. Were you running hot at idle or at speed? If at idle, you likely had an air leak- most likely a loose hose clamp. Its best to tighten them with a socket rather than a screwdriver. If at speed, then you either have a blockage in a line, a failing impeller, or a RWP needing a rebuild. ------------- |
Keeganino wrote:Posted By: ZenZeus
Date Posted: March-11-2011 at 4:53pm
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TR,
Thanks. The boat has not made it out of driveway. Still testing before first run. I changed temp unit and same problem - temp is starting at 200 and going over 240. I am thinking a few things: 1. vapor lock near sending unit - my test to remove cap from FWC and see if temp comes down. 2. test sending unit by running new wire to see if somehow the original wire is compromised and the OHMs have been modified to make gauge read high. 3. check with gauge manufacture VDO / telefelx to see what unit is designed for their gauge. How does that sound to you guys? |
Posted By: Keeganino
Date Posted: March-11-2011 at 4:59pm
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Good troubleshooting tips Tim thanks.
I think it would run hot after a WOT run and seemed to stay hot longer than usual. That was a few months ago now so I dont remember exactly what was going on. My RWP is 3 years old and seems to be in great shape. I pulled the impeller when I winterized and it looks good but I will replace it anyway. Could be a leak in the hose from the trans oil cooler since that is the only one I have not replaced. Blockage is certainly a possibility. I guess if its still running hot I will replace the hose and do a good poking around to look for blockage. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: WakeSlayer
Date Posted: March-11-2011 at 5:05pm
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As Pete stated earlier, you need to make certain that the gauge and sender are meant for each other. I had a similar problem when I redid the Mustang. The supplier had shipped the wrong pair, and I had haywire temp readings. I finally got them to their research and they provided the correct sender.
I always suggest that people get a laser temp gun. I like RayTek ones. They are cheap and are a great tool to have in the bag. edit: Make sure you don't use teflon or anything for a thread sealer on the sender. You lose your ground and it will not work. ------------- Mike N 1968 Mustang |
Posted By: ZenZeus
Date Posted: March-11-2011 at 5:10pm
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just opened cap to FWC and started motor.
for a brief second the temp did start out about 160, but climbed to over 240 within 2 minutes. Going to check ground on gauge. I know I need to check the temp gauge reading against actual temp of motor. any suggestions how to do that ? And where should i test ? (take sending unit out after heat up and test water under intake ???) fellas ? |
Posted By: Keeganino
Date Posted: March-11-2011 at 5:15pm
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I think the easiest way is with a laser temp gun as Mike suggested. Harbor Freight has one on sale right now.
Good to know about the teflon tape. My sender is wrapped in teflon for sure. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: Keeganino
Date Posted: March-11-2011 at 5:17pm
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Will teflon kill your oil pressure sender too. Have not been able to get that to work and know it is teflon taped too. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: ZenZeus
Date Posted: March-11-2011 at 5:19pm
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Wakeslayer thank you
I do have some pipe tread compound with teflon on unit threads ....I never knew that. I will clean and try and get back to you guys. |
Posted By: ZenZeus
Date Posted: March-11-2011 at 5:36pm
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Ok, cleaned the threads on both unit and intake.
Restarted with cap on and off of FWC and still Same Problem 
could my gauge not be grounded good. Will be at all day tomorrow. got to get some work done today. Need some suggestions. |
Posted By: TRBenj
Date Posted: March-11-2011 at 5:55pm
If youre seeing 200 degrees cold, then clearly you still have a mismatched gauge/sender. Where did you get the replacement? If you can hold your hand on the riser comfortably when the engine is supposedly "hot" then clearly you are not really overheating. ------------- |
Posted By: TRBenj
Date Posted: March-11-2011 at 5:57pm
Is it safe to presume that you returned the boat to idle after running at WOT? This is probably the most stringent test for the cooling system (very hard operation followed by minimal cooling ability at low RPM) so any weaknesses will reveal themselves. If getting back up on plane brought the temp back down, then you would likely have a minor air leak somewhere. ------------- |
Posted By: 8122pbrainard
Date Posted: March-11-2011 at 6:17pm
The engine block is the ground to the gauge. You should get zero ohms between the sender body and the block. The "hot" side to the circuit goes to the gauge itself. The ground on the gauge is only for the lighting. Sender resistance varies along with the temp it picks up and basically varies the voltage to the gauge. The temp gauge is really a volt meter. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: ZenZeus
Date Posted: March-11-2011 at 6:42pm
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ok,
Then maybe the original hot wire is compromised somewhere between gauge and unit ?? |
Posted By: Keeganino
Date Posted: March-11-2011 at 8:03pm
Its gonna be 65 here all weekend but I have too many things apart to go out for a test run. This sounds about right. I bet the original hose is cracked somewhere. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: 8122pbrainard
Date Posted: March-11-2011 at 10:00pm
No. If "comprimised", you ether wouldn't get any reading on the gauge (you do) or if the wire/connections/terminals corroded causing high resistance, then the gauge would read low. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Gary S
Date Posted: March-11-2011 at 11:15pm
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Im not sure if they are there on the weekends,but here is the VDO tech support line 1-800-265-1818 ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: WakeSlayer
Date Posted: March-12-2011 at 11:04am
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http://www.amazon.com/Raytek-MT6-Non-contact-MiniTemp-Thermometer/dp/B000O80B5M - Raytek Minitemp MT6 ------------- Mike N 1968 Mustang |
Posted By: ZenZeus
Date Posted: March-12-2011 at 2:54pm
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got one at harbor freight CEN - Tech.
Thanks for the suggestion though. Will get to some testing today. Thank you. |
Posted By: Keeganino
Date Posted: March-12-2011 at 3:16pm
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HF is having a huge sidewalk sale today. Might have to go check it out. Curious to see how the temp gun works. Let us know what you find. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: ZenZeus
Date Posted: March-12-2011 at 8:05pm
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OK fellas,
I got pics and videos for you. I look forward to hearing back you. Please take a minute to watch. Would appreciate some feedback when can. Thank you. https://www.filesanywhere.com/fs/v.aspx?v=8a6b658c596670b9a766 (copy and past in browser) I think the light smoke at end of video is from wrong breather or just oils and such from years of rebuilding - not sure. |
Posted By: ZenZeus
Date Posted: March-12-2011 at 8:06pm
| the video is 3-4 min long. will take a few min to load. |
Posted By: ZenZeus
Date Posted: March-12-2011 at 8:11pm
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Lets try this again:
GO HERE TO SEE VIDEO......... http://www.youtube.com/watch?v=sOEvmmjiwp0 Go HERE TO SEE PICTURES: https://www.filesanywhere.com/fs/v.aspx?v=8a6b658c596670b9a766# |
Posted By: ZenZeus
Date Posted: March-12-2011 at 8:19pm
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Opps broken link.
FOR PICS... https://www.filesanywhere.com/fs/v.aspx?v=8a6b658c596672b2a1a9 |
Posted By: ZenZeus
Date Posted: March-12-2011 at 8:51pm
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Let it run for about 6-7 minutes.
Smoke is coming from breather cap. I know I am suppose to have some kind of return hose from flame arrester to breather cap??? but my flame arrester does not have nipple for hose. These are automotive valve covers and breather. Could it also be the heating up of the gasket silcone used to but on V covers? It has been 3 years since I put them on and started motor? Took temps reading after 7 min. Both heads 122 degrees Both valve covers 84. both risers 70 Driver side manilfold 195-200 at base of triangle. Other manifold 135. |
Posted By: Gary S
Date Posted: March-12-2011 at 10:46pm
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Looks like you have a gauge problem.Did you run the boat before you rebuilt it? Or did this happen after the rebuild? Did you ever change senders? Have you disconnected the sender and then turned on the key? Did the gauge stay at zero? Where does the hose that comes from the pcv valve on the right valve cover go to? Sorry for all the questions ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: ZenZeus
Date Posted: March-12-2011 at 11:02pm
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Gary,
Never saw the boat run. It was partially sunk when i bought it. Yes, new senders, 1 from ski dim , 1 from quivra marine. Pics have code of sender. Looks to be correct one. Not sure if gauge is acurrate after 35 years ??? I did take wire off and turn key and zero was the outcome. touched it to ground and pegged it to hot. Changed sending unit and same thing. Hose goes from check valve to carb. thank you for asking the question. keep them coming. Mark |
Posted By: Gary S
Date Posted: March-12-2011 at 11:21pm
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I think you are getting the wrong senders.On a cold engine when you first go to start your already getting a temp reading?Might have to pull the gauge and see if it has any model numbers on the side or back of it and go from there. It's a Teleflex I assume? That number I posted is for VDO but those guy's were sharp maybe they could help. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Keeganino
Date Posted: March-12-2011 at 11:25pm
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Looks like a gauge problem.
edit: not in that I think the actual gauge is broken but rather the engine is running at normal temp and the reading is off. ------------- "working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger http://www.correctcraftfan.com/diaries/details.asp?ID=4897" rel="nofollow - 1973 Skier |
Posted By: Luchog
Date Posted: March-13-2011 at 4:38am
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Some vapor is normal if the engine sat for a long period.
Also the new paint will smoke a smell over a few thermal cycles. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |
Posted By: 8122pbrainard
Date Posted: March-13-2011 at 9:48am
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Rig up some cheap hose/duct like dryer venting to each exhaust and collect the water in seperate buckets. Run it and see how much difference you get in each. Have you contacted the company who made the FWC system to make sure it's plumbed correctly?
Have you ID'd the Ohm range the gauge needs? To check the sender, remove the wire, get a Ohm reading to the block and check that to the known temp. Do it at several temps. The Ohm to temp range is pretty linear. To check the gauge, you can remove it from the boat and hook it up on the bench with known values of resistors instead of the sender. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: ZenZeus
Date Posted: March-29-2011 at 5:47am
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Update on temp sending unit:
Called Teleflex, tech told me I need the sending unit TS26631. I was able to get one through west marine. Teleflex told me that the TS26631 has OHM range 240 cold / 33 hot. Bought one for $14. Put it in and getting same results. Up to 240. I am having trouble with my oil temp gauge (not moving under normal operation, but when grounded to block pegs to right) Any other tests I can do? |
Posted By: 8122pbrainard
Date Posted: March-29-2011 at 10:25am
Have you checked the actual temperature as recommended? IR temp gun? Also, some of the better digital volt ohm meters have a plug in thermocouple. You tape it close to the gauge sender. Bench test the gauge as mentioned? Check you voltage you get to the gauges. With the oil pressure gauge, check the ohms at sender same as recommended for the temp sender. Sender wire diconnected and with engine off and running at several different RPM's. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 82Fineline
Date Posted: April-04-2011 at 12:47am
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^What temps would you be expecting to see with the IR gun? Mine reads 150* on the gauge once warmed up, but if I use the gun on the intake and block it will read anywhere from 175 - 205. Im assuming this is normal as the sending unit is reading the water temp which is cooler than the actual engine?
Thanks! |
Posted By: ZenZeus
Date Posted: April-18-2011 at 4:01pm
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UPDATE!
Shaft alignment: Ok fellas, I got the shaft aligned to .001 tolerence. I used a half moon piece of shaft packing to align the shaft in shaft log - worked great. Gauges: Still having troubles with my gauges, temp sending unit, oil pressure and gas tank. I will get back to you on these. I have not been able to get a meter on the situation yet - next on the list after timing. TIMING: OK, I bought a aftermarket timing cover. I am now missing a timing pointer :( . I need help to determine what pointer i need (10 or 11 oclock) and maybe where to get one. Or maybe make my own and set the piston to TDC and use some timing tape on dampener to get a base reading - any suggestions. I am going to post some pics of my timing cover to see where it should mount. There is a little hole but not threaded - maybe a sheet metal screw ??? to hold . I would love to see a picture of what it should look like - anyone got one. My motor is a 351W reverse rotation. https://www.filesanywhere.com/fs/v.aspx?v=8a6b698e596773b46f99 LINKAGE for BW 1:1: First the tranny and gears all work fine. How do I begin to set the linkage correctly- should i set it a particular gear first then adjust???. I can either get it to go in forward and neutral, but not reverse or the opposite. Can't seem to get it to go in all 3 gears from the shifter (original shifter 1977) Seems Look forward to everyones help. Mark |