Oil in Engine Valley - Intake manifold R&R

[slagona]

My oil leak in my engine valley is back. The Injection Pump had 1-2 nuts loose when I purchased the truck, tightening the nuts seemed to have stopped the leaking for 4-5 months. But it is now leaking again. Nuts are still snug.

I want to fix the leak once and for all. Could the timing cover be leaking into the valley? Or is the cause the injection pump to timing cover seal? Any other thoughts?

If I'm going to remove the injection pump to reseal it, should I go as far as to R&R'ing the timing cover also - or is it unlikely that the timing cover would leak into the valley? Are they separate jobs in that I won't have to repeat work to do the timing cover after I've competed the pump R&R?

I was able to get the intake manifold off - and then back on in about 4 hours last night (10pm - 2am). That includes taping a new hole for the boost guage, and a spare for water injection if I ever get some time to play (a few years down the road). Not too bad of a job - it's tight getting the intake back in there. I'll probably do it again this weekend to reseal the pump, relocate the fuel filter, relocate the PMD. I hate oil leaks.

I wasn't able to determine exactly what is leaking oil. The only thing I really accomplised was getting dielectric grease in all of the connectors - and I only lost one nut.....

Suggestions appreciated.

[cruzer]

The injection pump to timing cover is a gasket. Has someone ever adjusted the timing? Maybe they screwed up the gasket. Has someone ever missed the oilfill and dumped oil in the valley?
Are you sure it's oil and not diesel fuel?

IIRC there is no gasket between timing cover to the front of the block. I think it is just glued together. FYI. To do timing cover removal you may have to remove pump or at least unbolt and leave the pump hanging by its injector lines. It could leak there but that would seem to me as a remote possibility. If your thinking timing cover removal, it is time to consider timing gears. If it were me, I would clean thouroughly and monitor the leaks to find exactly where it is b4 removing the timing cover. That considerable work that might fix a leak.

[slagona]

Cruzer,

Thanks for the reply. I agree, the timing cover is a remote posibility. The IP gasket may have been damaged when the nuts (2 of the 3) securing the pump were loose. If I do remove the timing cover, Gears will definitely go in. But I also think if it were the cover, it would be running down the front of the engine also.

If it is fuel - it would have to be coming from the pump - everything else was dry (filter, lines, ....). I think it is oil as there is no fuel smell at any time - but it could be fuel.....

I will clean everything up before going any further. It certainly could be the IP Gasket - maybe it just took 4-5 months to fill the valley high enough for the leak to appear on the driveway (a spot the size of a quarter overnight). It could also be fuel leaking from the IP.

The entire valley is wet - starting at the timing cover, so it is hard to determine where it is coming from - definitely has been leaking for a while. It's not fast enough to notice oil loss, but enough to leave marks.

Just wanted to see if I was missing anything.

[ucdavis]

B4 removing IP, I'd spend some time cleaning up & identifying the leak. If it's got black soot in it it's oil. If its just oily, it is fuel.
There have been leaks from the head oil galleries that are penetrated by the manifold bolts (several go in w/sealant) that leak onto the shoulder between manifold & head & that could run down into the valley. If that's your trouble spot I'd hate to see you have to attack it twice.
Gasket on IP is just paper, but where it contacts oil it isn't under pressure but more subject to oil splash, so it would tend to be not much of a leak there (unless the prior boob didn't use a gasket?). Easy to clean surfaces w/IP off. Use a piece of scotch tape to position new gasket on block to avoid tearing it (stupid thing wants to jump around while you're maneuvering the IP into place & I tore mine).
Hope this helps.

[patrick m.]

what if the oil psi switch has developed a leak, that switch can leak at the connector end and cause a big mess

[slagona]

It's hard to say where the leak is coming from. There was no sealant on the intake manifold bolts (cylinders 7 and 8) - so they may have been weeping - I sealed them up when re-installing. The engine slants slightly towards the rear - oil is present at the front. Could be wind pushng it up - but I really think something is leaking towards the front. It probably is not fuel, I totally removed the fuel filter assembly - it was completely dry.

When I first purchased the truck, a mechanic stated the IP had 2 nuts loose, and oil was leaking from that seal. He tightened them up, but I think it still may be leaking.

I cleaned up the engine last night - I'll take a look today and see if I can tell where things are starting to leak.

--Scott

[StephenA]

This may be a long shot, but last week I had fuel in the valley, after replacing the stock T-Stat with a robertshaw 195. The valve for the fuel drain is attached to one of the bolts on the T-stat housing, & through carelessness I nicked the tube which developed a slow leak that ultimately turned into a gusher. At first, it looked like oil, as it dissolved the old grease left inder the manifold from overfills.
Hope this helps

[tom.mcinerney]

I'd listen to Stephen A. I thought i had oil leak down front of my engine(timing cover/oil fill/harmonic balancer seal). It turned out the small hose [bypass?] from water pump[to crossover?] had leaked coolant which i mistook for oil.

[britannic]

Another thought:

If the IP to timing cover gasket is installed with a gasket that sticks on one surface when heated and it was installed so that it sticks to the pump, then as soon as the pump is moved, it may tear, since it's held captive by the 3 studs.

This happened on my engine and it will only leak into the valley, not down the front of the engine, although YMMV.

[slagona]

I've been thinking about relocating the Fuel Filter to a bracket which I'll fabricate that will mount the Fuel Filter off of the alternator bracket. There seems to be plenty of room there - might even put the by-pass oil filter there if there is room for two.

I'll do that as a first step in the process.

That will allow me to replace all of the hoses and keep a better eye on the situation.

I do think the intake manifold bolts (cylinders #7 and #8) were weeping oil, the valley was always "wet" in that area where the intake manifold meets the engine. Hopefully those are now sealed. The good thing about replacing the intake manifold gaskets is that the new gaskets were light in color - should give some indication as to where an intake leak is occuring, if any.

I don't have a gushing leak yet - after cleaning the engine valley, there are no drips hitting the ground after 35 miles of driving.

[cruzer]

IIRC the front manifold bolts have to be sealed also.(cylds 1 & 2)

[slagona]

Yes, I think that is correct also. Since the heads are interchangable, if #7 is open on one side, #2 will be open on the other..... Same goes for #1 and #8.

I couldn't remember (or see at 1am while installing...) if it was one or both bolts that go through for each of these cylinders - but I am sure that the intake manifold bolt towards the middle (inside bolt for each cylinder) of the engine does go through for cylinders #1, 2, 7, and 8.

Thanks,

--Scott

[turbovair]

I have a similar situation with a small fuel leak under the intake.I will be replacing all low pressure hoses when the intake is removed.Should this hose be purchased from the dealer, or will ordinary fuel line from auto parts house be sufficient?

[ucdavis]

ordinary fuel line is the ticket. Wrap it in the same kinda loom sleeve for abrasion any place it has the possibility of rubbing anything; cheap insurance.

[turbovair]

Found the fuel leak... A small return hose directly in front of the diesel pump, jumping the pump to a small stel manifold bridging the injectors. I guess I may have slightly disturbed it while installing a T-Stat housing bolt. It was leaking(dripping) from the steel manifold end.