I am in desperate need of a highly skilled Ford/Mercury mechanic who has excellent diagnostic skills that can diagnose an engine knock on my 1996 Mercury Villager 3.0 Liter engine. It developed an engine knock a week ago and after a couple "friends" listened to it I am told it is not a rod knock but exact location seems to elude them. The motor is smooth as silk when cold, but does have a knock when warmed up, the knock does go away when the engine rpm increases beyond 1500 or so and when it comes back down the knock comes back. I am told it is a lifter as when the oil pressure increases this silences the lifter. Does this make sense?
Should I just bring this to a ford dealer and bend over and hope they use lube... lol... and hope they have a tech who knows what he is doing, also how do I know he knows what he is doing?
Or does this justify taking the valve covers off and replacing the lifters in hopes that is the problem?
I am also told that maybe running the motor without the belts to eliminate any potential external vibrations might help and that I should remove each spark plug one at a time and if the sound goes away or the pitch changes I most likely have found my problem cylinder.

Any other suggestions would be great...
Thanks Bill

From your description, it sounds like a collapsed lifter. Have you listened to the engine with a mechanic's stethoscope? Remember, BRycraft, the top end of the engine is the last on the oil train and, usually, the first to experience problems, when there's a lubrication problem. Have you checked the oil pressure with a mechanical gauge? I would take it to Ford and have them give you a written repair estimate.

I have not tried checking the oil pressure with the gauge, but have listened with the stethoscope, it sounds a little more pronounced on the back bank then the front but its hard to tell. How do I check the oil pressure with a gauge, is there a particular one to purchase and is there a port and what does it tell me? Or where the problem might be.
Also I have checked prices from autozone to napa and prices for lifters range from$13 to $35 each, are the parts really that different because $13 X 6= $78 and $35X6=208 big difference, I am not cheap but I don't like to waste money either, I believe you get what you pay for but really what's the difference and does it really matter? What's your opinion?
Thanks do much Bill

I would not have a problem with the less expensive lifters from AutoZone--NAPA is often expensive. Have you checked RockAuto.com for their price? Just did ($26.79).

Remove the oil sender unit and connect an oil pressure gauge. Easy to do. Buy an inexpensive one from your local auto parts store. You may find out that the oil pressure is so low that the lifters are collapsing. It may indicate major engine problems, not just with the lifters; e.g. crankshaft journal wear or failing oil pump. Find out what range the oil pressure should be for your Villager.

I have the factory manual and think I remember the sender is over the oil filter right? if so and if it's the lifter would I see an abnormal reading? Or maybe not. The shop that tried fixing the rear main seal leak tried putting in stop leak last summer when it had a real small drip after they replaced the seal. That wouldn't cause this in the long run would it.
Never heard of that auto parts store but will look into it..
Thank You.
Bill

I HATE all stop leak products, because of the "law of unintended consequences." I suspect the lifter problem is now a function of using that product. It likely clogged the lifter.

This is why I recommend taking the car to the dealer for major engine and transmission work. No factory-trained Ford mechanic would every use such a product.

Guess the more information one has the easier it is to come to a conclusion.
Ya never know what tid bit of info is going to matter and I had a feeling. Guess I will just start replacing the lifters and hope that the stop leak didn't do any other damage. Might as well replace them all since the back lifter is the suspect ones and the front are easier, or do you not recommend replacing parts that are not a problem?
If it isn't broke don't fix it or in this case replace it just in case..
I REALLY appreciate your help...
Thanks Bill

I would defer to the mechanic, with an eye on the cost of replacing all of them. I would definitely start using your 5W-30 Mobil 1 to clean that engine up. Synthetics have a much higher natural detergency.

You might even hold off taking it to the dealer for a while. On line, check out Auto-RX. It's an ester-based product that does a superb job of safely cleaning sludged-up engines, including lifters. If you decide to go this route, hold off on using synthetics until you finish the Auto-RX treatment. It's best to use conventional oil with Auto-RX. Many people I respect use this product with great success.

I had used mobil 1 synthetic until the oil leak I had last summer when all the seals were replaced, and it still leaked just a little, so the shop recommended going back to conventional oil and then without my knowing they used stop leak because it still leaked just a little in the rear main and that stopped it, by then what could I do, their mechanics say its OK, so I was stuck with conventional. I wasn't happy because I swear by synthetic. They say older motors leak and thinner oils only make it worse, so what could I do, even though all seals shouldn't leak...
So it started leaking again over the winter. I bring it back in and they said they had to replace the front main seal with an oversized sleeve and seal, well its still leaking oil all over my driveway and now has an engine knock. Unless they never replaced the seal and tried another can of stop leak and that is why I have this knock and a leak, I mean what are the odds that a second seal didn't do the job that its still leaking just as bad and now I have a knock, I really didn't think of that until now... those sob's, I bet that is what happened... well they are going to fix that oil leak if they have to pay ford to do it...
So once the oil leak is stopped I might try synthetic again, but now I can't because it would pour out...
Thanks Bill...

That's a tough spot to be in. If the vehicle is a "keeper," you might want to take it to Ford and get an estimate to have it fixed, once and for all, properly. If it's leaking that much, I don't think anything less will make you happy. I'd get everything done right--seals and lifters.

Yea I know we put a lot into it and it's a great van, I have a feeling this shop kept it for 2 days for show, threw in a can of stop leak maybe even 2 cans figuring what do we have to lose give me a free oil change, if it stops the leak they save a day of labor, worse case it comes back and have to really do the work... I found out that the original owners of this particular shop last year were sent to jail for embezzling over $400,000 from the village, so now there are different owners. But I paid like $350 for the seals to be replaced so they should have to keep doing the job until its done right, then again at what point do I just eat that and have someone else redo it? It's a tough decision because I don't like throwing money away...

I hear you.