View Full Version : 4.9 timing chain replacement ?


forrest
03-28-08, 11:37 PM
My 92 Seville has just reached her sweet 16th birthday and has also just clicked over the 200,000 mile mark. I thought it might be nice to give her a new timing chain and sprockets for a present. As far as I know she has never had a new one or water pump. I got it at 140,000 miles. Would appreciate any "heads up" on problems that I might run into and any advice on how to do the job. Any tips on how to make it easier. I have a broken, front of car, left side of engine, motor mount that I'll be replacing as well. I'm going to do the pump and any seals and gaskets at the same time. I don't have the torx that's needed. Does anybody know what size it is? I'm also wondering if it's an "interference engine". Will a broken chain cause the pistons to smash into the valves or would it just be dead in the water?

I also have a question about distributor noise. Several months ago I was having idle problems ... the old surge at idle trip. I cleaned out the EGR tubes in the throttle body ... plugged up big time .. adjusted the TPS and base idle with the IAC motor retracted and threw in some new Bosh platinum plugs, No help. I recently flunked smog. I found that the EGR solenoid was giving it vacuum at idle and that I somehow had the timing set at 24 before TDC. Must have been too many Coronas that night. I just put in new Delco platinums and a new set of Delco wires. It's idling great and passed with flying colors! But, I digress .... I have a whirring noise coming from the distributor. I replaced the cap and rotor when I first put in the Bosh plugs and can't say as I remember the noise before that. Do they usually make any noise or is it possible that the rotor is hitting inside the cap? Or for that matter, a bad bearing in the dist or bad gear? I know I could tear it apart and have a "look see", but don't have the car handy at this time. I'm going to be ordering the parts tomorrow and wonder if a new dist and cap is in order or just a cap and rotor. Other than that, she's purring like a kitten. Thanks in advance for any replies.

awadecki
03-28-08, 11:55 PM
The water pump is not an easy change. You can say bye-bye to the torx bolt heads once you try to get them loose.

The distributor shouldn't make any noise. Might be a bad bearing. Probably best to pull it. If you have an idle surge, the gear might be well worn (I'm sure it is by this point). I had that problem on my 85 Deville: idle would surge, wouldn't settle down, etc. Turned out the gear was well worn. Replaced it and it's been fine ever since.

forrest
03-29-08, 12:32 AM
What's up with the torx bolts? I've seen that mentioned several times in various posts. Are they usually rusted or frozen in, or is it that the actual torx bit wants to strip out the inner part of the bolt, where it goes, frozen or not? I think at least one of mine is rather loose. I had a cooling system leak there and didn't have the right size torx bit. I just took the closest one I had and pushed to one side while trying to tighten. It stopped the leak so at least one of them was loose.

The idle problem has been solved. Changed the defective EGR solenoid that was giving me a big vacuum leak at idle.

The sound from the dist is like something rubbing as it spins. The kind of sound you get from a worn out alternator as it spins. I guess sounds are hard to describe. Sufice it to say, it's noticable only when the hood is open and not REAL loud.

Barrie1
03-30-08, 01:22 AM
I have a 1991 Fleetwood with the 4.9 which has recently started making a tapping type of noise. The noise is getting a wee bit louder and it sounds like its coming from the bottom end of the engine. This engine has been really cared for since new with all the fresh oil changes and so forth it ever needed. It now has 165,000 miles on it as of to-day but the noise is worrying me a lot. I also have a 1984 Seville Elaganta which has over 300,00 klms on it and is running just fine. Are these engines known for the crank bearings to go bad that quick? Thank you.

caddydaddy
03-30-08, 10:23 PM
I've had no problems with the torx bolts on the 3 Cad water pumps I've replaced. It does help to use sharp, fresh drivers, so they won't round.

forrest
03-31-08, 12:24 AM
I still need to buy one. Do you know what size it is?