Hi all,
Pretty new here. Recently purchased a 2.6L Gen1 advertised as having a fresh motor rebuild. Unfortunately a small oil leak has developed, coming from somewhere behind the motor and she just started billowing a bit of white smoke at start up. Goes away after the motor warms up.

Havent diagnosed either definitively, but after doing a lil reading, looks like the oil leak is likely either the plug at the rear of the head, head gasket, or valve cover gasket. It could be the rear main seal, but the oil seems to be coming for higher up. Also, the white smoke points to the head gasket. I'll be testing for the blown head gasket soon, and do a closer inspection to see exactly where the oil leak is coming from.

In the mean time I wanted to tap the board for any 'watch-out's' or 'look fors' regarding diagnosing these two issues, and fixing them. I took a look through DR1665's head-removal thread which was super helpful. I'll probably be ordering one of these replacement heads if it comes down to it, also found in DR1665's thread.

Secondly, I'm not familiar with these motors so I wanted to check to see if there was anything else I should definitely replace while I've got the head off. I know this can be a slippery slope! I'll be replacing the alternator since it seems to be on its way out.

Once I get around to doing it, I'll post a bunch of photos of the process here.

Thanks!
Roland

Did the previous owner mention why the engine was rebuilt? The 2.6 is very sensitive to being overheated - if your cooling system isn't functioning properly you will very likely blow a head gasket and/or crack the head. If the rebuilder used new gaskets and seals on the motor but didn't use any RTV at the corners of the rear semi-circular plug, that's more than likely the source of your leak.

Why do you feel that the alternator is on it's way out? I'd be doing a little more diagnosis before throwing a new alternator at it - are the battery terminal connections clean and tight? Is there corrosion in the cables themselves? Is the engine ground cable attached and making good electrical contact? Is the alternator belt tight? If the 'rebuilder" had the engine out of the vehicle then there's a good possibility of several of those issues being a problem rather than a failing alternator.

Thanks for the reply.
The engine was rebuilt because of balance shaft failure, I think because of improper chain tension (which resulted in oil pump inoperation=engine failure). The entire cooling system was replaced and is working well. The motor has remained within normal operating temps since I've owned it.

I'll definitely be checking the cam plug for oil leakage but even after pulling the hood, if I can't get a good look at it, I'll probably need to pull the head to know for sure. I'll need to pull it to replace/reseal the plug anyways. Might as well replace it with the non-jet valve head from Clearwater.

Alternator output is beginning to fluctuate with engine RPMs. This is visible in all the lighting at night, and it's worsening. The alternator belt is tensioned properly. Cables look ok, but I'll further inspect before replacing. Thanks for the suggestion.

The head doesn't need to be removed to replaced the semi-circular cam plug, it can be replaced simply by removing the valve cover.

If you do end up determining that the alternator is failing, do yourself a favor and source your replacement from somewhere other than AutoZone, otherwise you'll likely find yourself becoming really good at replacing your alternator on a yearly basis.

Ditto ryany.

Have your oem alternator rebuild instead of buying a "rebuilt" one. The failure rate on these is about 100% on this forum.

I suggest looking for the oil leak this way. Degrease the engine, and then puff baby powder on the suspected sites after a short run, then blow off the powder. The leak tracks should be obvious.

My primary suspect for an oil leak at the rear of the engine is the rear cam bearing cam, not the plug. You can pull the valve cover, use rubber glove fingers to hold in the lash addjusters in the rocker arms, then umbolt the cam bearing caps and rocker shafts and remove them. This frees the rear plug and reveals the ungasketed surface at the rear cam bearing cap. Reseal the plug with rtv, and put a smear of rtv on the metal/metal surface the where the rear caps mate up, being very careful not to block the oil passage thru the caps that feeds the rockers and valve train. Replace the rocker shafts/caps and put a smear of rtv on the right angles of the vavle cover gasket at the rear where they arc over the rear cap. I also reseal the semicircular packing at the from with rtv, although I've rarely seen leaks there. The rear cap/plug is a common leak source, since it sees pressurized oil in the vavle train oil passage and has no gasketing expect on the plug perimeter in the good plugs (usually metal with a rubber rim or heavy platic).

Dude. As much help as I've received from this community, I'm glad to know I've managed to give a little back.

Clearly, you have a good idea of all the little snags I've run into taking things apart, but I can't stress enough the importance of keeping your bolts in labeled ziplok baggies and tagging your electrical and vac connections as you disconnect. I suspect the amount of abuse these trucks see, it's important to get everything fully bolted back in. <img src="/forums/images/graemlins/notooth.gif" alt="" />

Thanks guys all great advice.
Good to know about the aftermarket alternators. I'll definitely have the oem one rebuilt...unless I get her apart only to realize an aftermarket one is in there.

The oil leak seems manageable. Sounds like there are only a few common culprits. The baby powder trick sounds like a good one, and I'll check out the rear cam bearing cap. Thanks ryany and fasteddy.

What I'm worried about most is the white smoke. Started her up today and loads of white smoke spews out of the tailpipe. The smoke eventually goes away after the motor warms up. It's never overheated or even come close to it, so I'm having trouble accepting its a blown head gasket. Anything else possibly causing this smoke other than what I'm fearing most, a crack in the head?

I'll be changing the oil this weekend, so I can inspect its color for contamination. Whats the best way to test for a cracked head/blown head gasket? I've heard of various procedures using compressed air with the radiator cap off.

THANKS AGAIN!

Radiator pressure tester borrowed from an auto parts house is the easiest way. Start up white smoke is probably water. If there's water in the oil it will look like chocolate Yoohoo, creamy tan instead of oilish. The water will be on the bottom so a short oil drain (let just a dollop out and replace the plug) will show that. If you drain it into a clear container you can see small water "bubbles" on the bottom.

There is a water jacket in the intake manifold, too, and is a possible source of water in the engine.

Checked the coolant for traces of oil and found none.
Checked the oil for traces of water and found none.
Spark plugs were all normal/healthy with the exception of a little oil on cylinder 4's.
Compression test results were consistent, albeit a hair high = all cylinders were in the 160-170psi range. (carbon build up?)

Watched the tailpipe during a morning warm-up and the smoke lasted for about 5 minutes then decreased significantly. There would be random intermittent bouts of increased smoke that would last a few seconds.

I'm wondering if the smoke I'm seeing is actually not water, but instead burning oil. It is definitely more white but could be classified as a very light grey (which I guess is technically white) <img src="/forums/images/graemlins/rolleyes.gif" alt="" />
Also, the smell is not at all sweet like burning antifreeze. It smells, well, more like burning oil. Also, come to think of it, the motor has been consuming more oil than usual. <img src="/forums/images/graemlins/notooth.gif" alt="" />

Any reason not to suspect a bad valve stem seal? If it is oil burning, and I'm now thinking it is, it must be coming down from the head since the compression test is telling me the rings are ok. I'm going do a leakdown test to make sure it isn't a bigger valve problem and to be sure it indeed isn't a cracked head/headgasket.

It sounds like valve stem seals to me.

Burning coolant will have a decidedly sweet smell to it, so taking a good whiff of the smoke coming out of your tailpipe might help you determine what is accompanying the air and fuel into your combustion chamber. Sniffing your tailpipe may not do much for your brain cells though...