broken camshaft?


Kelhasfun
10-02-2006, 03:57 PM
I got one for you auto enthusiast's, i have a '99 Grand Am 3.4L, automatic with 125K miles on it. This car seems to be a problematic car. I've had head gaskets replaced about a year ago, before that it was the transmission had to be serviced, and the anti-theft system etc and this camshaft problem has topped them all. I've never seen a camshaft break before except in a high performance motor. I'm wondering has anyone else experienced this sort of problem. I can't think of what else could be wrong because when I removed the front valve cover (the cylinders 2, 4, 6) I only have the rocker arms actuating on cylinder 2. Cylinders 4 and 6 aren't moving at all! The only thing I can think of is the camshaft broke in half. What would cause this I don't know? why this would have happened? I have a hard time believing that possibly the rear two camshaft bearings spun to where it blocked the oil passages and restricted the flow of oil to the lifters which would cause them not to work? I don't know maybe my theory's totally wrong, if anyone can share their experiences or shed some light onto this with their story I would appreciate it. thanx

xeroinfinity
10-02-2006, 04:18 PM
If your timing gears or chain broke it'll do the same thing.

The only camshafts I hav seen break is in the dual overhead cams set up and it was the chain that caused that too.

Also push rods bend and could cause this but unlikly unless the vavle lash wasnt set up correct when the head gaskets were installed.

Looks like you might hav to remove the passenger side of the motor and investigate whats going on, if its the chain/gear or the camshaft is broke.
Its easier to go in this way, instead on removing the intake.

dpinion
10-04-2006, 01:43 PM
Actually I had 2 cams break in mine. It turned out to be the fuel pump wasn't putting out enough pressure so there was some sort of kickback happening. I am not a mechanic so I can't tell you exactly what the problem was, but I know that it was the fuel pump causing the cams to break.

xeroinfinity
10-04-2006, 08:03 PM
fuel pump ?? :confused:

Kelhasfun
10-04-2006, 08:59 PM
hey xero thanx for the info. but i have a question. You said that if the timing chain or gears broke it would cause these rocker arms not to work. I've always known that when a timing chain breaks there's nothing to turn the camshaft so nothing should be moving, right? Why would it only actuate the valves on the cylinders 1 & 2 but not the other 4?

xeroinfinity
10-05-2006, 07:02 AM
Liike I had said before, wheather its a camshaft or the gears and chain , the only real way to KNOW whats going on is to take it apart.

The gears could be partially broken(missing teeth), but it could just be the lifters or pushrods bent, not allowing all the valve train to work.

Good Luck!

blabhern
10-13-2006, 02:31 PM
My daughter had a boyfriend with a 93 GA 2.3L engine. He had the engine apart and couldn't figure out why the car would only go up to 20 MPH and no faster. When I looked in, I saw the camshaft was broken in half. Don't know what caused it or if they ever fixed it, my daughter broke up with him soon after. Good choice right?

bjobotts
10-14-2006, 08:32 PM
Everyone thought my cam was broken on 2.3l 93 grand am but long story short turned out to be coil housing. Replaced and car ran fine again...never would have figured by symptoms car had. Just a thought

normj
04-10-2007, 07:01 PM
my son has a 94 berreta with a 3.1 vin code m his camshaft broke. i did a compression test cyl 1-4 have compression cyl 5and6 no comp at all. we pulled the engine took it apart and cam broke and the exhaust valves were bent when the pistons hit them. the 2.8 3.1 3.4 are all the same engine the blocks were bored out. the best repair is a rebuilt engine

snupytcb
04-10-2007, 07:25 PM
i have never seen it but it makes sense. if your belt broke cam would not turn. if belt slipped cam and rockers would move but just at the wrong time. does sound like broken cam.

xeroinfinity
04-10-2007, 10:47 PM
This is an old dead thread :disappoin
Please dont bring up threads older then 3 months :grinno:

This is closed!

Add your comment to this topic!