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Can a machine tell you when a timing chain is failing? (1998 Buick Park Avenue)

Can one of a auto garage’s diagnostic machine’s check to see if my timing chain needs to be replaced? Also I want to purchase one of your three dollar booklets called, “10 ways of ruining your car without even knowing about it.”

First question No. As to the booklet it does not show on the Shop Car Talk page . You need to be on the home page . Also I wonder if you are aware that the show in no longer being produced.

Check e-bay, Amazon, etc

if the timing chain needs replacing it generally make a lot of noise.

Timing chains usually make a lot of noise before they break. If it’s not making noise or hasn’t jumped time then I wouldn’t worry about it.

If you follow the engine oil change interval then a timing chain should easily last 250k+ miles. My 05 4runner had a chain. When I sold it with a little over 300k miles the chain was still good.

The only way to really tell is to inspect it. But that means removing the timing chain cover and all the gaskets/seals. At that point you might as well just replace it.

I have a friend who once had a Dodge Ram with the 3.9L V6 engine. The timing chain had stretched and was banging into the timing cover. It was also enough out of time from this that you got nice little pops out the exhaust upon deceleration. There were no check engine lights but the timing chain definitely needed to be changed. These engines were notorious for needing this. I looked into it and there was a newer timing set that resolved these issues. Leave it to Chrysler to cheap out and see what they could get away with…

While it’s convenient to replace the water pump coincidental with the timing chain on many cars I learned to recommend replacing the timing chain coincidental to the water pump on GM 3.8L and similar V-6s. Often the first warning of impending failure was a code for the cam angle sensor which would intermittently fail due to iron filings accumulating on the interrupter which usually occurred soon after the rattling on cold starts that few people ever paid any attention to. If driven until the chain jumps those engines died throwing plastic and aluminum from the cam gear into the pan which was a real pain to clean up.

Yes, certainly. Well, the technician with the proper equipment can. A mechanic with a quality multi-channel labscope and the right experience can tell you if the timing chain is stretched or sloppy, how many degrees variance there is on accel or decal, and many other things related to the condition of your engine.

But it sounds like you’re just talking about someone pulling fault codes and giving a list of recommended repairs.

By the way, if I recall, some of these engines were an interference design, meaning if the timing chain fails there will be internal engine damage that will require removal of the cylinder heads. And they don’t always give warning before they fail.

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Thank you for your answers!

God bless you!

Father Paul Grala

Jesus said,“With God all things are possible”(Mk 10:27).

My mechanic always said, if you get as far as to tear the motor down to the chain, you might as well replace it. I have heard a noisy chain makes slapping sounds. It appears to be very common on 2004-2008 F150 Fords, so listening to one might give you a clue to a failing chain or chain guides.

This year Park Avenue used the 3.8L engine. It’s a push rod design and I don’t believe it is an interference engine.

I’ve had two timing chain failures in my Buicks. The one just made a lot of noise hitting against the timing cover. The other one just stopped at a stop light when the plastic gears stripped. I was told that on the 3800’s the chains tend to go out after about 150,000 miles but mine were more into the 250-300 range. The only possible way to tell would be if the timing became erratic but that wasn’t my experience.

That 3.8 was an interference design and more than once I’ve had to pull heads after a chain jump. One happened right in front of the shop. Customer stopped at the gas pumps, went to start engine, and just freewheeled. Kissed 2 valves. That was a late 80s Park Avenue.

I gotta tell this tale. A 3.8L Buick drove up with a check engine light on and complaints of poor idle and intermittent difficult starts with well over 100K miles. The owner asked for the price of a tune up and I told him I would not tune the engine with the expectation that the problems would be solved so he drove 2 blocks to a “30 minute tune up” shop where after the tune up the car died backing out of the shop and the shop owner called me and explained the situation and the engine had ZERO compression. The owner had a wrecker bring the car to me and the owner hesitantly left the car with me for diagnosis with no guess at the cost, It turned out to be the timing chain and when called the owner insisted that the previous owner had gotten the chain replaced so I told him he was free to tow the are away owing the minimum shop fee. He chose to leave it and although I was correct in my diagnosis when I pulled the timing cover I regretted that he did. The chain had been replaced but both original gears were used and carpenters latex white caulk was used to seal the front. Luckily a new chain and all appropriate incidentals got the compression up but despite my cleaning the pan out I lined out the warranty due to finding the white putty sealing the intake manifold and being clueless what other trashy work had been done. To protect myself I rode with the owner for several miles to prove that the engine was running well at the time he paid for it, with cash, as I had insisted.

Those 3.8L Buick engines were great and if well maintained gave great service but because of their well earned reputations they sometimes got patched up by DIYers and shady shop owners. It seems like it was a code 43 that usually turned out to be the chain, a low 40s anyway, and when that code appeared on a car with well over 100K it was best to pull the timing cover.

If there’s no engine performance symptoms and no unusual noises there’s little chance of a timing chain problem. Engine performance issues and noises are the most common way to diagnose timing chain problems. The timing chain connects the timing for the crankshaft to the timing for the valves. If there’s a question about the timing chain function, a valve cover can be removed and the crankshaft turned by hand while measuring a valve’s position, checking for play and resultant backlash. That can be diagnostic.

Your post led me to read more on line about the subject. It seems that many pushrod engines are interference engines, especially as the compression ratio rises. If all that is true then the Corvette LS engines would be interference engines.

Yes, and this is nothing new. Timing chain interference engines predate timing belt interference engines by decades. Cadillac engines of the 60’s were an interference design. The venerable old Ford 302 was a valve bender for a number of years. Some of the old Mopar 318s were interference, though they would usually bend pushrods before bending valves. The 3.8 Buick was an interference motor for most of the 80’s and 90’s I believe.

The LS Series of engines, has had a few versions over the years. 4.8, 5.3, 6.0, 6.2, and I’m not certain that all are interference design but many of the 5.3s are.

Just curious, do you think my 73 Ford truck’s 302 is interference? 1973 is from the emissions-design-problem era and has quite a bit lower compression than earlier years 8.2 is its compression ratio as I recall. I’ve always been of the opinion this engine is non-interference, but I don’t recall now why I’ve thought that. Maybe somebody who worked on it told me that at some point. Or years ago I took an auto-repair night school class where I worked on the truck in their shop, maybe the instructor told me.