1994 Plymouth Acclaim CAM Shaft Keeps Breaking

FARREND

MEMBER
1994 PLYMOUTH ACCLAIM

Engine Mechanical problem
1994 Plymouth Acclaim

First, I wish to say that I don't know much about cars, and I need this info only so I can give it to my mechanic, who's been pretty good at dealing with my car problems up till this one.

I've had this car about a month, and it's of course secondhand. About a week after I got it, the camshaft broke. It had plenty of oil in it, but I hadn't had time to get an oil change yet. The mechanic put in a used cam shaft. Since that time, I got the oil changed. A few days ago, the cam shaft broke again. Given that the car had plenty of oil both times, and the second time even had new oil, and everything appears to be running fine for the most part, my mechanic, along with mechanically-inclined relatives of mine, is baffled as to what could be causing it to break.

I got to see the first cam shaft, but not the second. It was broken near a large gear-looking part at the end, if I remember right.

Please, if you can, tell me what's causing the cam shaft to break and what I should tell my mechanic so he can fix it.

5 Replies

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

Ask you mechanic to check to see if the head has been removed recently. If so what I feel has happened is that the head has been warped due to a blown head gasket, and the repairer has not had the head straightened and just re machined the face, this causes cam tunnel misalignment and this can result in the cam failing, check this out next.

Mark (mhpautos)

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Tuesday, February 23rd, 2010 AT 11:02 PM

CARADIODOC

MECHANIC
33,908 POSTS

Hi mh, Randy here. Which engine does this apply to? I saw this happen to a former student's Intrepid but I don't remember if it had the 3.3L or 3.5L. Those supposedly suffered from "core shift" and I'm told it was somewhat of a common problem.

My guess is you're referring to the four cylinder engines. Is that right? How common is it for this to happen if the head isn't checked for flatness?

Caradiodoc

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Wednesday, February 24th, 2010 AT 3:25 AM

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

My theory relates to any over head cam engine, I have seen this with Toyota's there is a limit allowed for head bend, beyond this limit, the head must be straightened, this is quite simple job for the machinist, but if the head is bent beyond allowable limits and it is just machined flat, the bend will cause the cam to stress and with hollow core cams, they snap, billet cams will tend to chew out cam journals.

Mark (mhpautos)

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Wednesday, February 24th, 2010 AT 4:35 AM

CARADIODOC

MECHANIC
33,908 POSTS

Thanks bunches. Brain fade is what happens after 24 hours without sleep. I was thinking about cam-in-block engines. I remember now that this is why overhead cam heads must be straightened instead of milled. Even had a training video that showed a company straightening older Escort heads.

Time for a nap! Thanks again.

Caradiodoc

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Wednesday, February 24th, 2010 AT 7:10 AM

FARREND

MEMBER
2 POSTS

Thanks for answering!

I do remember the mechanic saying it looked like someone had replaced the head recently the first time the cam shaft broke. I'll print this info out and give it to him next time I have the time to stop at his shop.