Author Topic: Timing chain question (91 318iS) (Read 6360 times)

arcter · « **on:** February 09, 2010, 01:30:05 PM »

Hey guys, I own a '91 318iS in very good condition. It always has run great but recently I've been hearing some sort of rattling/vibrating sounds coming from the engine, mostly at idle. Not very loud though. So yesterday morning I go out to start it and it just stumbles and dies. So I had it brought to my mechanic and he says that the timing chain 'jumped time' and so I'm looking at a timing chain / hardware job. Does that sound right? I trust the mechanic but I just have never heard of one doing something like that so early, considering the noise wasn't so bad. He says the engine is fine, is it possible for it to jump time and not damage the engine? It was not running when this happened, it just died immediately upon trying to start it.

Any thoughts? Thanks!

Choking Hazard · « **Reply #1 on:** February 09, 2010, 06:44:48 PM »

Yes. It should not be too difficult to correct though, unless you replace the timing chain which is a huge job. He can just re-index the timing by taking off the valve cover. You MUST get a new timing chain tensioner too. Amazing it did not break a valve....

flyinglizard · « **Reply #2 on:** February 09, 2010, 09:15:37 PM »

I have one inside that did that on Fri. It bent all the intake valves. The weak link is supposed to be the long chain guide. The 4 hole, driver side guide ,sheds the skin and drops the timing off. The chain looks OK but Iam putting a new one on anyway. I will measure it, and the new one for the guy that wanted to know the diff lenght. It has about a 1 in sag held sideways by the ends. This car ran perfect right up to quitting.(300K)
Also , I will pull the lower pan and clean out that mess and tighten up the oil pump tube and stuff...
Might as well fix the oil can leak also..
If it jumped Timing, it will be about 400$ parts and about 8-9hrs labor plus the head work.(

valves
If it really skipped all of the valves, it is about $100more.
1000$ +- is fair and the car should be good for another 200K
HTH, MM

arcter · « **Reply #3 on:** February 09, 2010, 10:27:21 PM »

So it sounds like it'd be very strange if it did skip all the valves? That makes me worry that it probably did and the mechanic isn't telling me (yet?).

flyinglizard · « **Reply #4 on:** February 09, 2010, 10:49:37 PM »

There are a few ways to see if they are bent with out removing the head. Air in the plug hole is the easiest. But keep in mind that if they hold pressure that it will turn the engine some to BDC. Also pull the cam and measure the valve ends to the surface. Bent will stay down some. A good bit on this engine. The valves are about 11-12$ each
Most 16V engines with chains, hit most of the whirlygigs. IMHO. More than about 20 * late should touch the valves.
It would surprise me if none were hit. I would bet 20$ that at least 4 are.

arcter · « **Reply #5 on:** February 09, 2010, 10:57:34 PM »

Quote from: flyinglizard;87051

There are a few ways to see if they are bent with out removing the head. Air in the plug hole is the easiest. But keep in mind that if they hold pressure that it will turn the engine some to BDC. Also pull the cam and measure the valve ends to the surface. Bent will stay down some. A good bit on this engine. The valves are about 11-12$ each
Most 16V engines with chains, hit most of the whirlygigs. IMHO. More than about 20 * late should touch the valves.
It would surprise me if none were hit. I would bet 20$ that at least 4 are.

Thanks for your replies and sorry but I just want to be prepared for what I might be in for. He told me $800 for the timing chain hardware replacement stuff but if we find out tomorrow, say, that 4 valves were bent, how much money am I probably looking at altogether?

flyinglizard · « **Reply #6 on:** February 09, 2010, 11:07:57 PM »

R &R head and repair. about 5 hrs over the front end labor ,maybe less. The head itself will be extra.
Just the head is usually about 800 -1000 complete, But you have labor stack time due to the timing chain also.
So for about what the car is worth, 1300-1400 for all??
I dont get that much at 60 per hour tho. I am slow also. old anal and careful. Good luck. MM

3bvert · « **Reply #7 on:** February 10, 2010, 09:19:37 AM »

arcter
where are you at, maybe you can find somone local to get you some advice
you can also check r3v club and look regional

but I would be surprised if you dont have bent valves
or it could be a simple fix and the shop where your at now is hosing you

BlueBMW · « **Reply #8 on:** February 10, 2010, 10:54:45 AM »

You don't want to sell the car do you?

arcter · « **Reply #9 on:** February 10, 2010, 08:26:14 PM »

Quote from: BlueBMW;87079

You don't want to sell the car do you?

Depends what the damage was or if there was any. The mechanic hasn't had time to work on it yet but he says he's very confident it didn't do any damage this time. They've run it a few times and it idles nice and smooth.

flyinglizard · « **Reply #10 on:** February 10, 2010, 08:34:27 PM »

Lucky. MM

BlueBMW · « **Reply #11 on:** February 10, 2010, 08:49:41 PM »

That's great news!

arcter · « **Reply #12 on:** February 13, 2010, 07:53:49 PM »

Thanks! 175 across all cylinders.

Fixing some other stuff while he's in there but I should be good as new on Monday.

Choking Hazard · « **Reply #13 on:** February 17, 2010, 11:11:30 PM »

Buy a lottery ticket.

arcter · « **Reply #14 on:** February 18, 2010, 08:46:06 PM »

Alright guys, I got the car back. It seems to be running well but there are a few things I noticed and thought I'd post.

First of all, it sounds a little different. Whenever the engine is revved you can hear an almost "winding" sound or something. I showed the sound to the two mechanics at the shop and they didn't think anything of it, but it didn't do it (maybe just not this loudly) before. Maybe just due to the new timing chain stuff?

The other thing is sometimes when I downshift now to slow down, I let my foot off the clutch slowly and it feels similar to the rumbling you get when a car is stalling but it doesn't and the revs are normal. Stops when I get the clutch to a certain point. Any ideas?

They did a lot of work so maybe I'm just expecting too much?

As far as the other stuff goes, it now is very quiet at idle and even in the morning when it's cold. It seems to idle as smoothly as before (I actually always did have an intake leak or something that sometimes caused a funny idle) and run as well.