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Buick Lacrosse 2006 3.8l 6 Engine Trouble

I have a Lacrosse that has 110,000 miles on its engine. The car has has regular maintenance and oil changes at suggested intervals ( 3000K). 2000 miles into this oil change, The engine developed a klunk type sound. I checked the oil and it was dirty so I took in for another oil change. I was quite surprised to hear that I needed a new engine immediately. They could not tell me what had failed but I was in need of a $4000.00 engine transplant.
I requested that they change the oil and give me back my car. I have taken it to another shop and they concur with shop one. Shop two took it to a third shop while they had it just to confirm. After the oil change, the repetitive clunk became a persistent tap. Is my engine really going to implode in the near future? Is there anything that can be done to extend the life of the car?
Does anyone have any experience with this problem?

Perplexed in Cleveland

Would you describe this sound as a knock?? it is Very hard to say from your description, but it sounds as if your lower end is about to go… At least that is what I am getting from this. Although the 3.8 is a near bulit proof motor and should last 250,000 easy with proper maitence. The one week spot on these motors are the intake manifold, they can develop an internal antifreeze leak and if gone unchecked can introduce water into your oil and this can wipe out the lower end very quickly. $$$ to doughnuts thats that happened to your car. Have you been looseing coolent??

I’m inclined to agree with gsrag.

When he refers to the “lower end”, he’s alluding to your crankshaft main bearings and your connecting rod bearings. The crankshaft and the connecting rods are kept away from the main bearings and connecting rod bearings by pumping oil through channels and in between the surfaces. The pressurized oil seperates the wear surfaces. However, every time the combustion process happens in the cylinder, it places a lot of load on the side of the crankshaft (called “lateral” load). If the oil is diluted with coolant, one of the byproducts can be loss of a good oil barrier between these surfaces and damage to the bearings. Once damaged, the next step is seizure and a dead engine. Whether it’ll happen in a day or a decade is impossible to predict without tearing down the engine.

Hopefully the attached drawing will help illustrate the problem.

I have to tell you, though…one of these shops should be able to define for you exactly what’s going on. And without knowing more specifics, I’m reluctant to acceprt that the engine us totally shot. There are too many other thing sthat can knock.

Did you say that the first place suggested a new engine when you took it to the second? If so, you didn’t get an unbiased second (or 3rd) opinion. Take it to another shop and just describe the symptoms. If you haven’t done it already, you might consider having a Buick dealer look at it. BTW, if the first shop was a quick lube store, I would be skeptical. This is where auto techs start out. The lack experience and the shop doesn’t have the tools to provide a good diagnosis.

Thank you for the replies.

The first shop is the Buick dealer that has done all the work over the years on the car. The second one is where I have had a lot of work done over the years on other cars. The coolant issue seems like a real possibility because it is rather difficult to see the level on this car and I might have missed a slow leak. I would suspect that it would not take much leakage to cause a problem. I do check the coolant levels when I check the oil. What type of test do they need to do to finish the diagnosis? The car has not been checked with any computer because there was no warning light. I would agree that it sound more like a knock and it seems to worsen as the engine warms up.
Also, is this a fixable problem without ripping the engine out?

Thanks Again for the help.
Still Perplexed in Cleveland

I think the damage is done, if the mechanics are right. It’s not something that will fix itself or get better. You eather need to have your lower end rebuilt or a new motor installed.

OKAY - Is the rebuild less expensive than a new motor? Also, What do I say to the mechanics to get a diagnosis of the problem?

Thanks again.

I hear legendary reliability for the 3.8L yet I know 3 people who maintain them and have replaced motors under 200k. Maybe some bad luck or tall tales?

Raj they can be near bulit proof, buy these manifolds have done many in. It’s a weak point in the design, fixed by the aftermarket.

Op the cheapest fix is a used motor out of a wrecked car, try

Raj is COMPLAINING about engines that make to to just under the 200K mark? I don’t think that’s an issue at all. I have seen many many 3.8L GM engines with over 250K, and a few with over 300K. That doesn’t mean that some have gone less than 150, but I don’t see that as an issue either.

The 3.8 is one of the best engines GM ever built and at one time they were going to discontinue it. Due to the popularity and uproar that erupted they kept it in production for longer than planned.

With any engine failure there’s always a story behind it. Just some food for thought, but seeing as how the oil was noticeably dirty after only 2k miles what about the possibility that someone just flat did not do the oil change? (Noticeably dirty is also a subjective opinion.)

Yet another scenario could be a botched oil change in which someone forgot to put the oil in. The red oil light and engine rattling jogged their memory and then oil was added; after the fact and too late. This scenario is not a rare one and can be near impossible to prove but at some point that botched oil change will rear its ugly head. It could have even been due to a mistake made 30k miles ago.

Anyway, just theorizin’ for a moment.

Thank you for all of the comments. The botched oil change scenario is something that I did not think of. Curiously, the engine picked up a tap immediately after the last oil change and the problem progressed with time . At 2000 miles, I took it back in. I have driven it for another 3000 miles and I have given up hope on finding a solution other than an engine replacement and the problem was getting louder and louder. With great regret, I got rid of the car yesterday. Even the Buick dealer did not want the car. I left Buick ,as a brand, behind me.

After the fact I guess, but Buicks are good cars and the 3.8 engine is near bullet-proof. If someone botched an oil change that is not the fault of the car or the people that built it. This occurs with every make of car.

Question though. Did you buy this car brand new (as in 4 or 5 miles on it) or was it purchased as a dealer demo, lease return, etc?

You state that you have had the oil changed at 3k miles intervals and I’m just wondering if that regimen was followed if the car was lease or used vehicle, etc.

I bought the car used with 26000 miles on it - it came out of a rental fleet so it could have been abused early in its life. My doubts as to how this car was handled early in its life sent me to a new car lot or three to try to replace it. I know far to many people who lease cars and don’t take car of them - I thought that a rental car fleet car was a safer bet than a leased used car. My hunch was wrong.

Rental cars are a toss-up. Most of the time they will be fine but they’re always a roll of the dice.
I used to work for a dealer who provided many cars to a national rental chain and it was not cost effective for this chain to send a car back for warranty repairs. Their fleet guys (who knew little of the make apparently) would attempt to do things themselves and more than once we got butchered cars back for repairs after they ran into a stone wall.

In one case, they determined that a rough idle and hesitation was due to the car needing an engine overhaul; and this was on a 1 year old car with 4k miles on it. You should have seen that poor engine when it got towed to us. Whoever “overhauled” this engine used a dozen tubes of RTV sealer on every part imaginable and it was being squashed out of the seams in globs. The actual cause of the problem was an iffy TPS switch; a known fault that was easily repairable under warranty.

A guy who works with my youngest son rented a car for a week about a year or so ago and was bragging about beating it into the pavement. It was such a mess that he did not even want to return it during normal business hours and chose to drop it off at 1 o’clock in the morning.

Bottom line is these things are a crap shoot and odds are that Buick was done in during the first 26k miles due to someone rather than the make of the car.

I am the perpetual optimist so I really thought that I had found a great car that would last a decade. I have always loved cars and I have taken care of the cars I have owned over my lifetime. I had a Thunderbird that I bought new and drove for 16 years and 220000 miles. I know the value of maintenance- I am surprised that so many people just don’t do it. The Buick had only needed Maintenance( oil, tires, brakes and belts) over the years- I thought I was headed in the right direction. My brother has a Pontiac with the same motor that died at 105000 from a similar problem. He bought it used also but he had a garage and a mechanic friend to do an engine replacement for just over a grand. I was not so lucky.

Thank you for the comments.

Had a Buick 3.8l lesabre that literally 5 shops said “junk it–not worth fixing an engine rod knock”. So I took it to a guy to have him swap the engine. Turned out not the engine–HARMONIC BALANCER…which is this big rubber piece between engine and tranny. $50 in parts delivering it to the guy and $300 labor. The car was still going fine at 265K miles–original engine was still super running!

That’s between the front of the crankshaft and the pulley for the belts (unless you really meant “flex plate”).

I assume after four years the problem has been resolved but yeah the balancer is on the front of the engine and the flywheel is between the engine and transmission. I’ve had three 3800’s that were great and got 120K, 350K, and 500K on them. One balancer was replaced under warranty at 50K and I’ve had to replace a couple more throughout the years. Usually doesn’t cause a knock though, just stall, rough running, etc. A flywheel could cause a tap I guess. Had to replace one of those on my diesel.