Mechanics

SL: TIMING CHAIN

1993 Saturn SL1 • 4 cylinder 2WD Manual •

After researching this site and others, here is how I can best explain this scenario.

Engine is the 1.9L SOHC LK0 or L24

Situation: While driving to work, my friend's car "seemed to be loosing power." When she got to work, parked it, only later to unsuccessfully start the car. The car was towed to a garage.

The garage said that she "broke" her timing chain and that it would need to be replaced and there might be possible engine damage.

So, after research, I feel I can replace the "broken" timing chain. If I did, I would buy a replacement kit, which includes the sprockets, the guides the tensioner and a new chain. Not really a big deal it seems.

However, as I have learned, since this engine is an "interference" engine, it is likely that upon failure of the timing chain, that any number of the valves could be bent and possibly the pistons bent as well.

Questions:

1. Is there a way I can (relatively) easily check to see if the valves and/or pistons are damaged?

2. If it is only bent valves, can I just replace the valves and get away with it?

3. If not, and the valves need replaced, what other valve related parts need replaced?

4. About 5 days prior to this problem, she had her oil pan replaced - could that have led to this problem, since the tensioner seems to be actuated hydraulically by the oil (i.E. A poor oil pan installation led to oil leakage, led to no tensioner actuation, led to chain slippage, etc.)?

Avatar
Alyoshablue
June 3, 2011.



If you have a bore scope you could go into the spark holes and try to see if the valves are closing all the way and not bent. Otherwise you would put a chain on and leave the front cover off perform a compression test on all the cylinders if you have good compression your ok. As far as if the valves are bent you would have to remove the head to see what you would need to replace at that point. Most of the time the pistons win and the valve bend and the pistons are ok. The oil pan being replaced and the timing chain being replaced I would think wouldn't be related. The timing chain tenisor is oil pressure feed but that is only used to take the slack out of the chain as it wears and stretches. There is a ratchet that locks the tensior as it extends out the oil pressure doesn't hold the tensioner in its position. Also ebay has some pretty good prices on the tenisoner kits.I would use the permatex ultra grey to reseal the front cover thats what I have been using.

Saturntech9
Jun 3, 2011.
Saturntech9: Thanks for those answers. Based upon your answer and what I have gathered throughout reading all the forums, it's likely that one or several of the valves are bent. So, I am going to assume that. However, it is possible that something else could be messed up so, here is my plan of action: 1. Put the new chain kit on and then perform a compression test. This would clue me into which cylinder has problems.

2. If there is a cylinder with a problem, I am going to have to remove the head and see what in that cylinder is causing the problem.

3. Replace any valves and valve components as needed (assuming the piston won this battle).

4. I would also get a new head gasket kit to replace and seal the gasket I am removing, since I am in there (using the Permatex Ultra Grey as needed).

5. Sounds like I should put new spark plugs in while I am at it.

So, Saturntech9, does that sound about right? Also, should I consider any water pump issues as a result of this mechanical issue - or is that not related?

Thanks again for your time.

Tiny
Alyoshablue
Jun 3, 2011.
Sounds like you have a great plan as far as the water pump goes it runs off the drive belt not the chain. If the water pump is not leaking or you can't take the pulley and move it side to side then I would not replace it.

Saturntech9
Jun 3, 2011.
Cool deal, saturntech9. I will be working on this the next few days and will close this thread with the results. Thanks, again.

Tiny
Alyoshablue
Jun 3, 2011.
Your welcome that's what were here for. Just a little tip when you put the front cover back on you must line up the oil pump in the front cover with the crank shaft as your putting it on use a small screwdriver to line it up that's what I use.

Saturntech9
Jun 3, 2011.
Saturntech9: Had a heck of a time with a few bolts, but I should have expected that with a car that is roughly 17 years old (thanks for PB Blaster). I am at a point where I am uncertain of something: 1. Do I have to remove the bolt on the crankshaft to remove the cover (thinking that it might be held in there by a slotted fit and I might just have to tug on it)?

2. Do I have to remove the bolt on the top center fly-wheel to remove the cover (I am thinking I don't since it seems it might fixed to the cover itself).

Assuming I had to remove the crankshaft bolt (5/8" I believe), I was trying to wedge a socket handle (and other stiff objects) against the crankshaft pulley to keep it from rotating, while I tried to unloosen the nut - but to no avail. That is why I asked the question above.

Again, thanks for all your help.

Alyoshablue

Tiny
Alyoshablue
Jun 8, 2011.
Yes the balancer has to come off it's a 21mm bolt its very tight i would remove the little flywheel cover get a flywheel holding tool and hold the flywheel while someone breaks the bolt loose with a breaker bar.The flywheel cover has three 8mm bolts holding it on there is also a brace that goes from the engine to transmission.Here is that flywheel tool iam talking about unless you have a very strong impact that is your best bet.

http://www.amazon.com/Powerbuilt-648455-Flywheel-Turning-Tool/dp/B001CZJ4J0/ref=pd_sbs_auto_1

Saturntech9
Jun 8, 2011.
Saturntech9: I've broken two ratchet sets trying to loosen the bolt on the "balancer" - which connects to the crankshaft. I went to Autozone last night in search of the fly wheel tool you suggested and after talking with the folks there, the said, "just get an electric (I forget) drill, which you can purchase at Harbor Freight for the maximum of $50. Makes sense, as it seems I can't provide enough torque on the bolt. Let me know if that makes sense.

Additionally, what seemed to be a simple experience of give and take, posting on this site, this job is taking on some elements which are requiring specific questions and a considerable amount of time on my behalf and ultimately, your behalf. So, in good conscious, I don't feel comfortable continuing the back and forth without compensating you for your knowledge and time. I would not know how to proceed with this, however, if you were to agree with this, it might make sense to just send you a check? I believe in what goes around, comes around - and you've been more than generous with your time.

Thanks, Saturntech9.

Tiny
Alyoshablue
Jun 9, 2011.
You shouldn't be using a ratchet to break that loose breaker bar's are used for that I like suggested before a 1/2" drive one that is over 24" long the longer the better. That electric impact gun that the guy at auto zone suggested at harbor freight isn't going to break loose that crankshaft pulley it isn't strong enough. If you want to waste your money and give it try you can. They are usually very tight I have taken a lot of them off I worked for saturn for over 16yrs so I have taken a ton of them out. Most of the time there very tight I have seen a few that wernt that tight but I think someone must have had that bolt out before. You can pick up a breaker bar and socket at harbor if you want. Keep looking for the flywheel holder if you see any tool trucks stop at the auto repair shops like a mac, snap on, matco, or a cornwell tools truck go see if they have one on there truck. If you want to leave me a donation all you have to do is start a new question title it donation and then where you would fill in the question part put this donation is for saturntech9.

Saturntech9
Jun 9, 2011.
ST9: You were absolutely right on the best method to remove that bolt - using a breaker bar with an extension is the best way (for the sake of it, I did try my neighbor's 7.5 Amp electric impact wrench and it didn't even touch it). Here was the setup (in case it helps someone else): I used all impact "grade" socket components just in case the torque would be too great. 21mm socket, (2) 8in socket extensions, 1/2in breaker bar and a 48" pipe. I set up two concrete pavers along side the car, placed the car's tire jack on top of them and raised it to the height of the bolt. Instead of a flywheel tool, which would have been ideal, I used the car jack's wrench as a stop in the flywheel (probably not ideal). I aligned everything and carefully cranked down on bolt and had it off in less than 10 seconds - amazingly easy. The flywheel came off without the special tool I signed out from Advanced Auto.

One note - where is the harmonic balancer on this thing? Is it on the other side?

Anyway, I removed the timing cover to reveal a slight horror. The two guides for the chain were nowhere to be found and the tensioner was half gone. Both sprockets had teeth that were worn down to nubs. Also, the chain really ground away at some of the surfaces and one of the guide bolts, leaving the remaining oil full of aluminum and other filings. Further, with all the metal filings in the oil, here is my plan from here - in addition to the head work above: 1. Drop the oil pan and drain all oil.
2. Replace the oil filter.
3. Clean the crankshaft housing, and valve cover housing and rocker arm/cam shaft housing.

Also, what is that component on the inside of the timing cover, sandwiched between the cover and a bolted on casing (where the crankshaft bolt and lower sprocket go through)?

It really feels good to get the bolt off and obviously, could not be done without your help. Thanks.

Tiny
Alyoshablue
Jun 13, 2011.
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