engine leak input required

[dsmyth]

This is an 85 with 60k, but lots of years. Currently taking engine apart and found these oily messes. . Never saw any oil drips underneath but would have soon no doubt . Suggestions ,even though the oil cooler doesn't seem to leak should I replace the seals? thanks Doug

[James Brown]

looks like the thermostat and the tensioner oil lines, both easy fixes. Replace the oil breather gasket and the idiot light switch also as there prone to fail.

[KTL]

Doug,

Those are fairly easy fixes, especially considering that you have the engine out.

Picture #1 shows the leak coming from the engine's internal thermostat unit. Thoroughly clean around the damp area and you'll find an alloy cap-looking piece. Take off the two M6 nuts and carefully (careful not to gouge the case) pry the t-stat unit upward out of the engine case. On the t-stat body you'll find an o-ring you need to replace. Next to that leak is another usual leak suspect- the oil warning light sending unit. That sender is usually a wise one to replace if it's old, because they eventually leak around the plastic-to-metal crimp location.

The other leak in picture #1 is the engine case breather hose. This hose gets hard and looses it's flexibility. A new hose that is snugly clamped to the breather housing will solve that leak no problem.

Picture #2 is a leak coming from the camshaft oil feed line. A new cam line, a compression ferrule and a new compression nut are the simple fix. Also get some new crush washers to re-seal the banjo bolt connection you'll disconnect near the valve cover (far rt. side).

Also check that wire harness that goes into the fan shroud for the alternator. That one has been known to get brittle and sometimes overheats. If you see any signs of brown/black on the wires going to the alternator, look the harness over real good and decide whether or not it should be replaced.

[aigel]

Absolutely replace the oil cooler seals (o-rings). Now it is easy to get to them. You other ones may be tight now but 6 months away from leaking. If you have new seals, you get a new start. I would actually reseal the entire engine. Replace every seal you can get to without major disassembly.

George

[kidrock]

thanks Kevin, for that detailed explanation...I guess it really helps to have pictures of the common culprits.

I plan on getting around to a small drip I currently have, but I was waiting for a reason for my first P-car engine drop.

[rnln]

obviously the oil cam line is leaking, the line to the right of the pressure sensor.

[dsmyth]

Thanks Kevin for the thorough explanation and the others for your suggestion. I really wasn't expecting this mess because it never dripped oil under the car. It did come through to the interior from time to time when it must have been dripping on some hot exhaust part. I am going to order every seal or part that could possibly be leaking or could leak in the future and completely reseal it as suggested. thanks Doug

[dsmyth]

I just reread the suggestions and went out to check the breather hose and the last three inches is as solid as steel. Great tip as I would have missed that one. thanks again. Doug

[KTL]

Alot of people say to replace the breather housing gasket on the case, but usually it's that pesky rubber hose that is the culprit! Also carefully remove those plastic nubs/pins that are inserted into the breather neck. They are supposed to provide a barb that holds the hose onto the neck. The hose stays on the neck just fine w/out them. The reason I say remove them is because the plastic points inside the neck are very brittle and if they fall off at some point, they’re going into the engine case.

Some say the crankshaft radial seals are good ones to do while you're in there. If those aren't leaking, don't bother. They last a long time and aren't all that leak prone. Sometimes replacing them is a bad idea if you don’t install them well. Also, the crank seal on the A/C & alternator pulley side is notorious for looking like it leaks when it really doesn't. Often it's the crankshaft #8 main bearing o-ring that's the problem and that's not going to get replaced w/out opening the engine (split the case halves).

Chain box covers- not often leaky. But if they are you're wise to also replace the sometimes brittle chain ramps while the chain box is open.

Look behind the chain box covers to see if you find any leakage. There is a paper camshaft seal that is leak prone. This one’s a PITA to replace because you have to remove the chain tensioner, cam sprocket (some specialty tools needed), chain box, and replace the paper gasket on the cam tower in addition to the o-ring on the camshaft cover. Only reason I mention it is because this job is MUCH easier to do with the engine out because the camshaft cover is a bugger to get out and you also have to reset the cam timing.

Oil cooler seals are indeed leak-prone and it's MUCH easier to R&R the oil cooler with the engine out of the car. Also check the S-hose to the oil tank for the same brittle condition you saw on the breather hose

Check cam lines and oil pressure sending unit area- lots of seal rings here.

Check valve covers + there's no better time than right now to adjust your cyl. head valve clearances with the engine out. If your lower valve covers are leaky, consider having a machine shop put them on a grinder table to “deck” the surfaces to make them flat & true.

Intake manifold gaskets- check the barrel nuts for looseness. If loose, remove the intake and put new gaskets (12- yeah, what a pain in the arse) between the intake and the cyl. Heads.

Oil return tubes on bottom of cylinder heads. These are most easily fixed with the exhaust removed, but don’t go there w/out proper removal of the exhaust nuts (heat to cherry red to avoid stud breakage)

Check the main fuel line that runs under the intake manifold and Y’s into the fuel injector rails. If original, the hose is notorious for leaking at the swivel joints- VERY DANGEROUS. Shoot us a picture if you’re not sure whether or not it’s original. Again, it’s much easier to replace with the engine out of the car. Do a search and you’ll find all sorts of solutions for replacing this line (new factory redesigned line {expensive}, custom braided stainless line made from your old line, or self-repair with new hose and crimp clamps.)

Cyl head temperature sensor- check for two wires coming from this sensor. The older 1-wire sensor is failure prone and kinda tough to replace with engine installed.

Motronic reference sensors at engine-transmission interface- the wire sheathing on these suckers gets old & cracked and lets the wiring corrode, giving intermittent operation. Look closely at these sensors. If bad wire sheathing, consider replacing them.

Clean and repack your inboard CV joints, check all four boots.

I see you’ve got the trans separated from the engine, so that invites some more inspection:

Clutch & flywheel & disc. A lot of people say to replace the clutch while in there. I think that’s wasteful. Clutches last a long time, so if the pressure plate surface is not abused (no grooving, no blueing from excessive heat), I’d reuse it- especially since you’ve only got 60K on the clock. That’s not a lot of miles if the clutch was used properly w/out over-slipping it and proper rev-matching on downshifts. However the release bearing should be replaced. The flywheel can be resurfaced with a minimal double cut by a machine shop. The disc should be replaced if the rivets are the same height as the friction material.

Check the condition of the guide tube on the trans input shaft. Replace if worn/grooved heavily. You can also rotate it 180 degrees if you notice wear on one side only. If you remove the guide tube, DO NOT re-use the notoriously strippable Phillips head screws. They’re basic metric screws that you can reproduce at your local hardware store.

Check the trans input shaft seal behind the guide tube. If leaking, replace this one.

Check the shifter shaft seal. This one is also leak prone, so replace if it’s very wet & dirty around the shaft

Check the trans. Output axles radial seals. These are also leak prone and a lot of people ignore them. They’re easy to replace and you can make a simple press tool to install the new ones. I made my tool out of a 2 in. diam. Piece of PVC plumbing pipe, a pipe cap and some threaded rod.

Any o-ring or rubber seal that you replace should be treated with silicone paste like Sil-Glyde, Permatex Disc Brake Lubricant, Dow Corning 111 or 112, or similar. This stuff not only lubricates the o-ring or seal, but also protects it from oils, greases, ozone, etc. that break down these rubber parts.

[NOLAsc]

Going on 11 months later, but... Kevin, thanks for the thoroughness of your response.