Timing chain/timing chain tensioner gone.

[JFleury8469]

Well, I'm a little sore that my first post on this forum involves serious damage to my GA but here goes.

So I was cruising down the interstate headed back to VT from NH and I gassed it a little to pass someone, and the whole car lost all power, revs dropped to ~1000 and shortly after that the engine died. Pulled over and tried to start it again and nothing, plus the engine sounds different while cranking.

Had it towed to a nearby repair shop and they said the timing chain and/or tensioner is shot. I would just like some clarification/confirmation about whether the engine is damaged and in what way and maybe what it would cost to fix.

Thanks

[Mike Jung]

6-hours book labour rate, IIRC...for a timing chain & water pump change service.

Don't you love the 2.4L Twin Cam 4-cylinder engine ?

Also, while you have it opened up:
Change the water pump, & flush & re-fill your engine coolant.

So, maybe minimum $600+

But since the timing chain broke on you, more.
Since you probable have to fix some values too (?).


PS: Why did you wait so long to get it serviced ?
The timing chain must of been noisy at cold start-ups.

[JFleury8469]

Probably should have clarified, this is the 3400 v6. The chain was making no noise, this was basically a no-warning situation. At this point is it worth going to pick it up and bring it back ~150 miles (one-way)? I was also told the piston may have smashed the valves, is this true?

[cardude007617]

hmmm i thought the timing chain never was really an issue on the V6s....

[lone_wolf025]

For a timing chain to fail is extremely rare unless its way past the recommended change. As for engine damage, that depends. I don't know if the 3400 is an interference engine or not, but what it boils down to is that if it is and your chain did fail, chances are good you're gonna have major engine work done. Interference engines are ones where when valves are down and pistons are at top dead center they can smash and "interfere" with each other. I'll see if I can find the info before someone else chimes in.

Edit:

Can't find anything specific but someone with a 3.1 had the bent valves to show its an interference engine and that's basically the same engine for the most part as the 3.4. So I'm thinking yea you'll be lucky if you don't wind up with cracked heads if it is one.

[cardude007617]

at this point he would be better off getting a low mileage junk yard motor or something to put in instead of trying to fix his own of there is extensive motor damage. :/ quite the ****ty deal

[AaronGTR]

Are you sure they didn't mean the serpentine belt and tensioner? The timing chain is under the front cover and it doesn't have a tensioner. It has a damper, and it controls the rotation of hte camshaft relative to the crank. When a timing chain goes the engine does not just quietly shut off. It's usually accompanied by lots of broken valves and pistons.

There is a much better chance though that the belt tensioner broke since that's a common problem, and losing the serpentine belt would make the engine shut off since all your accessories wouldn't be turning anymore (alternator, water pump, power steering, A/C).

[stewartfn18]

Originally Posted by AaronGTR

Are you sure they didn't mean the serpentine belt and tensioner? The timing chain is under the front cover and it doesn't have a tensioner. It has a damper, and it controls the rotation of hte camshaft relative to the crank. When a timing chain goes the engine does not just quietly shut off. It's usually accompanied by lots of broken valves and pistons.

There is a much better chance though that the belt tensioner broke since that's a common problem, and losing the serpentine belt would make the engine shut off since all your accessories wouldn't be turning anymore (alternator, water pump, power steering, A/C).

wellllll, the car COULD still run without a serp, belt, but like you said all of the acc. are not spinning, so you would lose PS, power would be pulled from the bat instead of the alt, no more ac...you get the point OP. but like everyone else has said the timing chain on the 3400 is very robust and is not prone to failure. how many miles are on the car?

[JFleury8469]

Well when I bought the car the engine was supposedly blown so I had a new (used) engine dropped in for $1300 (~700-800 for the engine, the rest was labor) . It had around 100k miles less than the car (or so my mechanic told me) so now its probably around 48k on the engine.

I don't know if this makes any difference but when I cranked the engine to try to start it, it sounded entirely different than the other 1000 times I've started it and one of the guys I work with said that it was def. the timing chain so I'm still not 100% sure.

I think I'm just gonna go down there with a car dolly and bring it back up here for my mechanic to take a look at it. Thanks for all the answers/advice, I appreciate it.

[lone_wolf025]

Originally Posted by JFleury8469

Well when I bought the car the engine was supposedly blown so I had a new (used) engine dropped in for $1300 (~700-800 for the engine, the rest was labor) . It had around 100k miles less than the car (or so my mechanic told me) so now its probably around 48k on the engine.

I don't know if this makes any difference but when I cranked the engine to try to start it, it sounded entirely different than the other 1000 times I've started it and one of the guys I work with said that it was def. the timing chain so I'm still not 100% sure.

I think I'm just gonna go down there with a car dolly and bring it back up here for my mechanic to take a look at it. Thanks for all the answers/advice, I appreciate it.

There's one easy way to see if this isn't a case of belt gone bad vs chain failure. Pop the hood and see if you still have a belt tight against the pulleys. If you do, chances are your coworker might be right.

Anyone find out for sure if the 3400 is an interference engine or not?

[JFleury8469]

Yeah, the serpentine belt is definitely still there. That was one of my first thoughts while I was coasting "Did my serpentine belt just snap???" hahaha. My biggest problem now is trying to find a truck that I can use with a U-Haul car dolly to get the car and where to come up with the money for gas and the rental. FML

[lone_wolf025]

Sorry to hear that but maybe you'll get lucky and have minimal damage if any. It might not be likely but until you open the engine or someone knowledge says for sure its non-interference, you still got a shot.

[Malaclypse]

The 3400 is an interference engine as far as I know.

The only non-interference engine GM has used in recent memory was the 3.4 DOHC that was phased out in '97.

[juanvan]

There was a list somewhere on google with the mechanic list of all the interference engines. I can't find it now though. I was searching for a Honda B21A1 - the timing belt went in that car 4yrs premature - have to replace the head on it, but its not making any noise and one of the cylinders is at 15psi. still running though

[JFleury8469]

Not sure if this is true for the chain equipped engines as well, but this is a chart for belt equipped engines.

GM Timing Belt Tech Data and Replacement Intervals

[lone_wolf025]

Chains last much longer than belts. I just flipped through my owners manual and there is no mention of checking the timing chain. Granted the service recommendations are one step short of useless, if it was a timing belt it'd be mentioned. If I recall correctly chains should be checked every 100,000 miles.

I just heard a quick and easy way to check. Take out a spark plug, ground it, and put you finger over the hole and have someone bump the engine over with the starter. If you feel it sucking at your finger and blowing out you have some compression. You could also pull off one of the valve covers and see if the rockers move when you turn it over. If it passes both tests the chain is intact still. To confirm without a doubt do compression tests on a couple of cylinders. If you have compression on both timing chain is not the issue.

[JFleury8469]

Well the part I was concerned about was the "Interference" column, it says "No" but I'm not sure if this applies to the chain-equipped engine as well.

Just got off the phone with U-Haul too, they said the Jeep I was gonna use ('98 Grand Cherokee Laredo) is not heavy enough to tow the trailer/car combination. This is turning into more of a headache than I though it was going to be.

[lone_wolf025]

Originally Posted by JFleury8469

Well the part I was concerned about was the "Interference" column, it says "No" but I'm not sure if this applies to the chain-equipped engine as well.

Just got off the phone with U-Haul too, they said the Jeep I was gonna use ('98 Grand Cherokee Laredo) is not heavy enough to tow the trailer/car combination. This is turning into more of a headache than I though it was going to be.

It could go either way. If it is interference, not much more damage you could do than is already done. If not then you'll be alright.

It might be cheaper to just arrange to have a towtruck pick up your car and take you back. I assume you've looked into that already?

[JFleury8469]

Well the trailer I was going to use is about $45 for the day, and depending on what vehicle I use it'd be around $50-75 for fuel VS. 100 miles at $3/mile or more calling a tow truck. I'm pretty much at a dead end here unless I hear from some of the people I've talked to about a truck.

[lone_wolf025]

Whats the cost of renting a uhaul truck one way?