pinging/oil loss/bad mpg

[CougarX]

I've been chasing a problem on my 92 for the last month or so. When the engine is under load (usually accelerating at the top of 4th gear on the expressway) it pings. I'm loosing about 1.5 of oil quarts every 3000 miles. Lastly, I've lost about 2-3 MPG. I'm assuming that these are all related somehow but have yet to figure it out.
I've cleaned the MAF sensor and the throttle body, changed the plugs, wires and air filter, and reset the computer. None of this has helped at all and I'm running out of things to do, with the exception of taking it to a garage ($$$). Anybody else have these problems? Any Suggestions? The explorer is completely stock except for 30" tires and has 137000 miles on it. Thanks in advance.

Brad
92 XLT 4x4

 

[Ira]

First thing I would recommend is doing a compression test. With the oil loss, first thing I would think of would be bad rings. This could just be the result of engine wear.

Do you have a problem of loosing a small amount of coolant each week? If so, there was a problem on the earlier models with an intake gasket leak. I may be wrong but from what I remember, the torque on the bolts would either loosen off or the gasket would start to wear and it would cause coolant to leak slowly into the engine. This could be the cause of your MPG decrease. You may just want to try and retorque your intake manifold and see if that helps anything.

The pinging you are hearing could actually just be the lifters pecking. Old oil or the lack of oil can cause this. Another possibility is varnish/sludge build-up in the engine especially in the lifters causing a restriction in the amount of oil that can pass thru. The easiest fix, if that is your problem, is a product called CD-2. You can get it at any parts place and even Wal-mart. It is an oil based detergent that helps to remove the sludge inside of the engine. It is like the detergent that is in the oil only it is more concentrated. About a 12 ounce can is $2-3 and it can work wonders in an engine that has some wear. If necessary, I think you can use 2 cans if your engine is bad enough. Just pour it into your oil.

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Ira
91 XLT 4x4
What do Playboy and National Geographic have in common? Just a couple of the places I will never get to visit Dead Link Removed

[This message has been edited by Ira (edited 02-13-2000).]

 

[Explorerdude]

Ira,
That detergent stuff really works?? Dead Link Removed I always use to think it was joke. I take it the stuff you're talking about is that STP oil treatment stuff.

Would it be worth it to put a can in your engine at oil change if you get a moderate chatter at highway speeds?? I have a 94 with 94,000 miles on it and I seem to get that chatter Brad's talking about. I do need to change my oil though. It's been 3K miles...

Any suggestions??? My MAF is spotless. I did notice that my throttle body gets carbon build up and generally needs cleaning about every 6K miles. Is that normal?? I did have a problem with carbon build up on my MAF but I fixed that with one cleaning.

A friend has an older 300 straight six in an F150 that seems to have a really terrible carbon build up problem... You'll clean it and by the next month it'll be all built up again...

What causes carbon build up??? What can you do to correct it besides owning stock in NAPA?? Dead Link Removed

Thanks in advance!

Happy Wheelin',

Joe Dead Link Removed

94 Explorer XLT
33X10.50 BFG AT KO's
4" Superlift Suspension
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"What doesn't kill ya only makes you stronger!!"

 

[CougarX]

Thanks for the info about the gasket. Come to think about it, I think the #5 plug did look slightly different then the rest of the plugs. Should I try retorquing the intake manifold bolts before trying the gasket or should I just replace the gasket for good measure?
I havn't lost any coolant so I'm pretty sure that it's not that. How much does the replacement gasket cost? Can I get it at a parts house or do I have to go to a dealer to get it?
One last thing, how does the Throttle Body manage to get carbonated if only air passes through it?

Brad
92 XLT 4x4

 

[Ira]

Joe,
The stuff I am talking about is actually called CD-2. It is different from the STP oil treatment. STP is mostly used to improve viscosity from what I remember. I personally do not use it. I have heard some bad things about it. CD-2 is about the same viscosity as regular oil. I cannot remember who makes it but it is readily available in the automotive dept at Wal-mart. It is available in 2 different types that I can remember. One is for reducing engine smoke and the other is the detergent which even says on the front about quietening (sp?) noisy lifters. The can is white and has a yellow oval on it from what I recall and is cylinder shaped (about 2 1/2" in diameter and about 8" tall). I would recommend this over all the other types. As I said before, it may take 2 bottles in severe cases. I think they recommend adding 1 bottle with each oil change but I would put 2 in it to start with if the oil change is not immediately due.

Carbon build-up is just a normal effect of an engine. All of them get it with time, but bad or sticking rings can cause it faster. Bad fuel, incomplete combustion, and oil burning will also speed the process up. Don't quote me but from what I can remember, on my model, there is a hose going from the oil fill tube back into the air intake system before the intake and throttle body. When you have blowby in the engine, this is causing an oily smoke to enter the TB and can also accelerate carbon build-up. Believe it or not, water is one of the easiest ways of removing the carbon while the engine is running. This is done by using a spray bottle with a fine mist spray and spraying it into the air duct after the airbox. I am not recommending doing this but while the engine is idleing or slightly above, this spray can be introduced and you will see the exhaust turn black as it is working. I don't know exactly which additives are best to use for carbon removal in the automotive industry, but in the marine industry, there is a product called Carbon Guard made by OMC (Johnson and Evinrude manufacturer) that is simply mixed into the fuel tank and it helps to dissolve the carbon as the engine is run.

Brad,
I would recommend just retorqueing the intake first. If after a week, this does not work, then it may be time to change the gasket. I don't know what a gasket costs since I have not had to change mine.

Hope this info helps you out. Keep us informed of what you find.

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Ira
91 XLT 4x4
What do Playboy and National Geographic have in common? Just a couple of the places I will never get to visit

 

[victorb]

Brad,
I, too, had the same problems you are discribing. The oil loss, pinging and lower than usual milage. I replaced the intake manifold gasket(s) and am now a happy camper. I have a '92 XL 4X4, 4.0Litre pushrod engine with 230,000kms. There is a kit available for the intake gasket replacement. I paid about $70.00cdn. The valve cover gaskets (not in the kit that I bought)were another $60.00. There are 2 intake manifold gaskets - upper and lower. Start to finish, it took me about 8 to 10 hours. (My mechanical abilities are about 4 or 5 out of 10) I also went and bought the Chilton manual.
Email me if I can be of any more help.

 

[jake]

My guess is you've got a leaking intake manifold gasket. On the OHV engine that gasket runs under the rocker cover similar to the old 390 V8. When it leaks, it pulls oil from the rocker gallery. Since oil reduces the octane of the mixture, you get pinging. Also the air leakage will cause that cylinder to run lean. The closed-loop fuel system will drive the overall mixture rich trying to compensate, and that reduces your fuel economy.

If you're handy, replace the gaskets. If you're not, pay somebody to do it. Continuing to run with the leaking gasket can cause piston damage.

 

[Ira]

Joe,
Check your belt to see if it is tight. If it is loose, it can cause squealing. It is also possible you have something like a power steering pump that may be getting tight and you may hear the belt slipping. As the engine runs for a minute or so, it is loosening up.

As for a bad intake gasket causing pinging, it could be a couple of things. First, it could be allowing the engine to pull in extra air thru the leak causing a lean condition. Another thing, if the oil is leaking and getting in the cylinder, it could cause pinging from the air/oil mixture being a lower octane. If water is getting into the cylinder from the leak, this could cause it too.

I think what a lot of people call pinging, is not really pinging. I think they hear the lifters clattering from deposits or old oil and they think this is pinging.

I would wait a week or so and see if retorqueing the intake took care of the problem. A lot of times, the gasket is not destroyed and when it is retorqued, it will take care of the leak. If not, then I would change it.

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Ira
91 XLT 4x4
What do Playboy and National Geographic have in common? Just a couple of the places I will never get to visit

 

[Ira]

Jake,
I swear, I did not copy your post. While I was typing, you were posting and I did not see it until after I posted. At least we agree on what can be happening.

What can I say...Great Minds Think Alike...LOL.

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Ira
91 XLT 4x4
What do Playboy and National Geographic have in common? Just a couple of the places I will never get to visit

 

[Explorerdude]

I'm not getting any noticeable leaks. (It's not leaving any spots on the driveway) However before I changed my oil I had the oil light come on and when I checked it, it was a quart low. I changed the oil and it didn't smell burnt or anything. I checked it after I ran it today and yesterday and both times it was in the hatch marks so it's not leaking any. I think I'll torque the intake down to spec and see if that doesn't eliminate any problems. Thanks for that info.

Happy Wheelin',

Joe Dead Link Removed
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What doesn't kill ya only makes ya stronger!! Dead Link Removed

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[Explorerdude]

Victor,
Why would a bad intake gasket cause pinging?? Just curious.

Ira,
I put in a can of CD-2. It seems to work pretty good. I might try the intake gasket replacement and see if that doesn't help any. What causes a serpintine to squeal?? I bought some belt dressing and put it on it but it seems to still squeal whenever I first start it. I visually inspected it and everything seems to be alright. Any ideas??

Thanks,

Joe Dead Link Removed