1988 351 xlt weird oil leak.

[ryanapfel]

I have a pretty bad leaking comeing from the rear pasanger side mostly. The weird thing is it only happends when i get into higher rpms. I can sit and idle for an hour and not see a leak. If i drive it i leak. The higher the rpms i get the more it leaks. It looks like most of the oil is coming down the back passanger onto the starter and then down to the pan and off the pan into a puddle. It also doesnt leak when the truck is turned off. If i let it cool iff and whipe it down i never get another drop. Any ideas? I already changed the pcv valve and the oil pan gasket with no luck. Thanks

 

[Krafty]

have a look at your valve cover gaskets. your oil system would pressurize when driving pushing oil into your valve covers and thus leaking. when idleing the engine produces lower oil pressure and thus less leaking.

 

[ryanapfel]

Well when i replaced my pcv valve i looked around and it doesnt seem wet up there. my whole engine is compleatly coverd in oil so its kinda hard. If its not the valve cover gasket it's gotta be the head gasket right? Or possibly the rear main?

 

[ryanapfel]

Basicly what it comes down to is if there is some east spot to check for an easy fix or should i just rip the engine out and replace all the gaskets all the way around

 

[Rons beast]

If the engine is covered in oil, clean it dillegently first. Even the back where you say the leak seems to be. Then dust the engine with baby powder. Run the engine at the rpm that had produced the leak, and look for the highest point where oil appears. there is your leak. You may need a mirror to get a look at the back of the block.

Good Luck

 

[Krafty]

another option that isnt as messsy as baby powder is a florescent dye product. you put it in your oil and let it leak for a little bit then with a flashlight you should be able to see clearly where it is coming from but it is probably more expensive than the baby powder. and like ron said you HAVE to clean up your engine so you can accurately detect the source of the leak.

 

[ryanapfel]

The only spot left is the head gasket and the valve cover gasket correct? Both require the top end to be torn apart so i may as well tear it all apart and replace all of them. Im not gonna go threw all the hassle to replace one to have another start leaking later.

What it comes down basicly what im asking. Regardless of where its leaking i need to take the engine out and replace the gasket. So if i take it out and replace them all (like i would do even if i knew where the leak was) ill fix the problem correct? I just dont want to take the whole thing out to replace them to find out it was some sensor or somthing in the side of the block i didnt know about.

 

[Bully Bob]

"If its not the valve cover gasket it's gotta be the head gasket right? Or possibly the rear main?"

Could be a head gasket, but not as likely.

What's in that area is;

Head, valve cover, pan, rear main, & the rear of the intake manifold.

Take a look at the back of the intake. :-B

 

[ryanapfel]

Its kinda hard to see vack there obviously. Is there a good way to check? Or just fish around the back with a hand to see if its wet?

 

[ryanapfel]

Okay so heres a lil side question. Say it is the head/intake/valve cover leaking. Is it worth it to pull the engine to replace em all or is it easier to replace them while its still in.

 

[Bully Bob]

Any of those, it would be much easier to do on the veh. The main "PITA" is removing/moving all the smog junk & wiring, etc. The rest is easy... [-o<

(If memory serves., the rear main can be repl. with the pan off.)

You can use a "dental mirror" & flashlight, as stated, or the like, to see back there. You can wipe it clean by hand if necess. so as to get a better read.

& OOPS., I forgot, some eng. have a soft-plug over the back cam bearing hole. It's quite rare but they can sometimes rot/leak/fail.

As for pull'n the eng., that would depend on it's condition. If it's a "run-out" & due for re-build., then yes.

 

[ryanapfel]

Thanks for the help guys. Sounds like unless someone else can come up with a brilliant idea to get it to stop leaking by monday. Im pullin it out and replacing all the gaskets

 

[Krafty]

unless you plan on rebuilding the engine there is no need to rip it all apart just for gaskets, replace the one or ones that are leaking and leave the rest alone until you decide to do a rebuild. no point ripping all apart changing all the gaskets, putting it all back together to find out shortly down the road that you need to rip it all apart again to do piston rings or main bearing and replace the gaskets again anyways.

just a waste of time and money if you ask me. head gaskets rarely leak outside the block without leaking inside the cylinders as well, which would cause excessive smoke. therefor I must lean toward a $20 valve cover gasket and maybe an hour of wrenching.

you do know how much work is involved in just removing the engine? not to mention tearing it down?

 

[Bully Bob]

"....brilliant idea to get it to stop leaking by monday."

Ya..., this ain't gonna happen...!

Any "brilliance" will have to come fr. you as only you have eyes, ears, & hands on..!

All we can do is point to the most obvious options.

Yep., you'll need to pack a few lunches, call in the "beer truck" & round up a friend or two if you intend to R&R the eng. $-) ( /emoticons/[email protected] 2x" width="20" height="20" />

 

[ryanapfel]

Dont u think its stupid to take all the time to tear it apart to replace one gasket and not the others? Seems like your asking it to leak out of the other side next month and have to tear or apart again. I guess ill start with the valve cover gaskets as they are the easiest to get to. And work my way down till its fixed. I have to believe its the intake though..... i think its hard to believe that the valve cover is onlyleaking out the back and not the rest.

 

[Bully Bob]

"Dont u think its stupid to take all the time to tear it apart to replace one gasket"

NO..! not at all....it's done all the time. (may end up with a 20 min. repair)

Don't read so much into it. Wait 'til you find the leak.

No need to take valve cover off unless it is the "leak" ..!

Also., in order to make a "PUDDLE" it must be a big hole..!!

------FIND IT....Then we'll know what action to take. -----

We'll stick with ya but you gotta take the proper steps. It's not all that hard [-X

 

[ryanapfel]

Yea its a pretty bad leak. I cant drive it on the freeway cuz it dumps too much oil on the exhaust and smokes me out

 

[ryanapfel]

So heres an update if anyone is interested. The valve cover gasket was cracked and leaking crazy out the back of it. So changed both if them and ot slowed the leak WAY DOWN. still have a leak though. I believe the rest is coming from the oil pan? Thes one spot its dripping from and thats the bottom of the bell housing on the tranny? Gotta be the pan right? Or could that be the rear main?

 

[Krafty]

could be either, id wipe off the bell housing and oil pan and try ron's baby powder trick on the oil pan and see what happens.