Guesses about what's wrong with my car?

[leebee]

One of our cars is a 2005 PT Cruiser with 129,000 miles on it. I am seeing two "issues" with it. First: It runs fine on the city streets, unless the a/c is running. If I'm using the a/c and I stop at a light, intersection, whatever, it runs fine for a bit and then the engine gives a shudder, and this happens cyclicly; it's almost like when a 4 cylinder car is only running on 3 cylinders. It ONLY happens when the a/c is running and the car is stopped; when driving with the a/c, there's no problem. Second issue is that when the car runs on the highway between 65mph and 73mph, there's a shimmy in the steering wheel. No problems below or above these speeds, no issues with it pulling or shimmying when I apply the brakes, etc.

Anyone have any guesses about what either of these could be? I am going to take it to the CarGuy in a couple of weeks (we aren't driving it now, waiting for the credit card to cycle around... story of my life) but want to have some idea of what the issues might be, before he gives me his best guess!

 

[PrincessShmoo]

One of our cars is a 2005 PT Cruiser with 129,000 miles on it. I am seeing two "issues" with it. First: It runs fine on the city streets, unless the a/c is running. If I'm using the a/c and I stop at a light, intersection, whatever, it runs fine for a bit and then the engine gives a shudder, and this happens cyclicly; it's almost like when a 4 cylinder car is only running on 3 cylinders. It ONLY happens when the a/c is running and the car is stopped; when driving with the a/c, there's no problem. Second issue is that when the car runs on the highway between 65mph and 73mph, there's a shimmy in the steering wheel. No problems below or above these speeds, no issues with it pulling or shimmying when I apply the brakes, etc.

Anyone have any guesses about what either of these could be? I am going to take it to the CarGuy in a couple of weeks (we aren't driving it now, waiting for the credit card to cycle around... story of my life) but want to have some idea of what the issues might be, before he gives me his best guess!

Purely a guess here - re the shuddering at stop while AC on. The AC cycles on and off as necessary to provide the correct temperature. The cycling may just be more noticeable while stopped. When you're travelling, you have road textures that may mask it more.

The second issue - wheel balance off? I think that only shows up at certain speeds, depending on how badly it's out of balance.

 

[sam_gordon]

One of our cars is a 2005 PT Cruiser with 129,000 miles on it. I am seeing two "issues" with it. First: It runs fine on the city streets, unless the a/c is running. If I'm using the a/c and I stop at a light, intersection, whatever, it runs fine for a bit and then the engine gives a shudder, and this happens cyclicly; it's almost like when a 4 cylinder car is only running on 3 cylinders. It ONLY happens when the a/c is running and the car is stopped; when driving with the a/c, there's no problem. Second issue is that when the car runs on the highway between 65mph and 73mph, there's a shimmy in the steering wheel. No problems below or above these speeds, no issues with it pulling or shimmying when I apply the brakes, etc.

Anyone have any guesses about what either of these could be? I am going to take it to the CarGuy in a couple of weeks (we aren't driving it now, waiting for the credit card to cycle around... story of my life) but want to have some idea of what the issues might be, before he gives me his best guess!

I am not a car guy and I didn't stay at a Holiday Inn Express last night. My guess on the A/C is the A/C motor is drawing too much current. When you're driving, the RPMs are up and the engine can handle the added draw. When you're stopped and at idle, the engine isn't supplying enough power.

The shimmying I'm guessing is a tire (or more than one) out of balance.

 

[runwad]

Yep you need an alignment on the shimmying, I've had that happen to me. No clue on the other, good luck!

 

[Marchand63]

Not a car guy but my suggestion......take it to a car guy

 

[Klayfish]

Both problems could be one of a few different things.

With the a/c, is it just a quick shudder and it goes away? Does your a/c stop working? If it's just a quick shudder and all else is normal, most likely it's just the compressor kicking off or on. With that age, Chryslers'...uh...quality (no offense, but there's a reason not many PT Cruisers are still on the road), it's possible the motor mounts are worn out. When the compressor kicks off or on, the engine will shudder a little more than it did when new. You don't notice it happening when the car is in motion because of noise and regular road vibration. Not saying that IS the problem, as I'm not quite sure of all the specific symptoms, and there are other possibilities. But that's what it sounds like from what you describe, just a/c cycling off and on. The compressor could also be starting to fail.

For problem 2, does the car track straight if you take your hands off the wheel (just briefly and keep them close...don't start texting...LOL)? It could be a wheel out of balance (lost a wheel weight), could be a tire with a damaged cord, could be a wheel bearing, could be bent rim. That'll have to be looked at by a shop. What does your tire wear look like?

 

[tvguy]

The A/C. Could be a bad solenoid. There is usually one that speeds up engine speed slightly when the a/c is turned on since it puts a load on the engine.

On the shimmy. Could be alignment, could be an out of balance tire, could be loose hub nuts.

A good mechanic is what you need.

 

[BigAlsGal]

The problem is it's a Chrysler. Haha! Jk.

 

[leebee]

It's been a pretty good car for us, and is a lot of fun to drive. Tire wear isn't bad, and is even. We'll see... I was just wondering if my thoughts were on the right track/looking for new ideas (I never would have known about the solenoid, for example). I have a good car guy who is on vacation for the first 2 weeks of October, so the Nugget (gold pt cruiser) will sit in the yard for a bit until he can come back and check it out- and hopefully it'll pass inspection!

 

[low-key]

Im not a car guy but I do know this, what ever is the most expensive that is it

 

[Klayfish]

It's been a pretty good car for us, and is a lot of fun to drive. Tire wear isn't bad, and is even. We'll see... I was just wondering if my thoughts were on the right track/looking for new ideas (I never would have known about the solenoid, for example). I have a good car guy who is on vacation for the first 2 weeks of October, so the Nugget (gold pt cruiser) will sit in the yard for a bit until he can come back and check it out- and hopefully it'll pass inspection!

From the symptoms you describe, I don't see any reason to park it. Again, without seeing the car, it's nearly impossible to say...just a car guys educated guess. If it's just a quick shudder and then all is normal, it's very likely something to do with the a/c cycling off an on...doubt it's a solenoid or anything like that. A minor vibration at certain speed is something to have checked out, but not something you'd need to stop driving it immediately.

 

[Micca]

Im not a car guy but I do know this, what ever is the most expensive that is it

..and there will be 2 options: You can repair it (the part), or replace it. The repair cost will be 89% of the total replacement cost.