Engine shaking on startup then smoothing out

engines

#1

Hi all. I have recently bought a 99 chrysler concorde lxi. Shorty after buying it the check engine light came on. I then took it to the dealership and they fixed the problem. Later on that same day my engine temperature light came on. I took the car to jiffylube the next mourning and got a coolant exchange. The car was still overheating. Not trusting the dealership (they said they did a 5 point inspection) I reaserched for a reputable local mechanic. After finding one, I took the car to him and he said the radiator cap was missing. He replaced this. After driving it back home and some other places first, the coolant starting coming out the top of the coolant cap. I also noticed while starting the engine it shakes and the rpms jump up and down. The jump is minor only jumping from 2rpm back down to 1 rpm, repeating once, then idiling out normally. While driving the car I also notice small shakes while idiling at a stop. I am not very car smart so does anyone have any ideas on what is going on with my car? The car has 113k miles on it and I’m having the timing belt changed this friday. I would also like to have my shaking problem fixed aswell. Thanks guys and gals.


#2

additional info…I live in Las Vegas, NV and the temperature is in the 100’s here already.


#3

You might have a head gasket issue, have that looked into.

In any case, get this overheating rough running stuff taken care of before you invest in a new timing belt. If you needed a new head gasket plus a timing belt you could be getting close to $2k in repairs…And another thing, don’t ever go to Jiffy Lube for anything, ever.


#4

Ok will do. I opened up my user manual and saw all the 100k maintenace that needs to be done to the car. Im sure the previous ownner didn’t do any of thse. Im going to replace spark plugs, replace ignition cables, replace timing belt, adjust drive belt tension, and have them inspect engine mounts and replace if necessary. I don’t have the slightest clue as to what any of that means or will do but its the required maintenace listed. Hopefully this will cure my problems.


#5

By the tone of this and MANY other posts, today, a car mechanics income is almost UNLIMITED…


#6

Since you may have purchased a pig in a poke that might have some serious issues the one thing you should NOT do is replace the timing belt at this point. There is no sense in spending a bunch of money on this repair until it is known if a serious engine problem exists.

I would advise running a dry compression test first and follow that up with a wet compression test if problems appear to be present. Some other tests may be needed if a faulty head gasket is suspected.

Based on what posters have related on this forum in the past about compression readings, apparently some mechanics don’t understand exactly what constitutes a good compression reading.
If you get this done post back with the figures; either for advice on bad ones or to verify if the good ones are actually good enough.