Dipstick tube reads way past full, 5qts

The 351 is supposed to take 5qts including the filter correct? When i have 4 total in the system it reads full on the dipstick. 5 puts it about 2-3 inches above the full dot. I even took the oil drainage hose off to get every drop of old oil out before filling it up. What gives?

Check sig, 84 so its normal, thats good to know...

yea, it still reads high, i always fill the filter first so its already got about 75% of the oil it can hold in it when i first start it

The same thing happen to me. I drained her and filled up with 5 Qt per spec. It was way too full. I ended up draining about a quart or more and slowly filled it to get it right.

For me I think it was due to the location of the drain(hose inlet) and the incline caused by the trailer.

I did also notice that when I drained and refilled it didnt take a whole lot to move the oil on the fill mark. 1/4 Qt moved it up 1/8 of an inch. So go slow towards the end.

79nautique wrote: if you are filling the oil filter then installing it, which I don't see the need to due, but to each there own. Then adding 5qt of oil you are adding to much oil.

no, no, no. I put about 1/2 a qt in the filter, then the other 4 1/2 into the fill hole. The trailer is in the garage and the jack isnt full extended or anything like that, ill try checking the level on the water tommarow and see.

The manual in the reference section states 4qts plus one for the filter, so that would be 5 qts the last time I went math class.

Set your trailer in a way that the engine is setting level in the boat. I beleive the engine angle that is necesary for the propshaft is what is giving you a false reading on your dipstick. I use 5qts in my '86.

Im still running 5, just wanted to make sure, b/c i read the manual that said 5. Just wanted to know why the dipstick is reading high. O well, i forgot to look at it while i was out today on the water. Im not having any problems, so ill just stick w/ 5.

Obviously there are a lot of us with the same problem and I do beleive these engines need 5 quarts so here is a procedure I had to perform on my motorhome because there was a service bulletin on it having the wrong dipstick.

IF you all agree then I'm going to do this next oil change.

Warm and completely drain the oil, remove filter. Replace with new empty filter. Fill the engine with 4 quarts of oil. Run engine for a few minutes. Shut down and let it sit for 10 minutes. Remove and wipe dipstick then reinsert and with a file make a file mark at the oil level. Then add 1 more quart of oil , run engine for a few minutes. Shut it down and let it sit for 10 minutes. Get a new reading on the dipstick and file another mark. The top mark is your full and the bottom mark is 1 quart down. I think this would be best performed with the boat sitting in the water.

Not sure who to blame, CC or the marinization company of your engines but this certainly looks like an oversight thats been going on for a long time.

What do you think?

81nautique,
Your proceedure sounds exactly right to me. BTW, my '78 351 Commander dipstick is the opposite. It reads low when I put five quarts in it. Does anyone know if the Commander uses the same oil pan (5qts) as the PCM? ...or should I use 6 quarts as my dipstick suggests?

If also comes into play...how well was it drained. If the engine is warmed up for the time it needs...oil will drain well...however, if you do it in the drive and don' run it long enough...it won't all drain out.

My 351 and the two 302's have crank case capacities of 4 quarts...I give it about 1/2 to 3/4's of a quart more, cause the filter won't hold a full quart. If you do overfill a bit...it can be noticed in the bilge ...often blowing back through the dipstick. This weekend I noticed this...dropped some out and all was well.