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Symptoms of a chipped piston

Gasnmyveins

New member
I'm looking at a GTP owned by people who don't know anything about working on a car themselves. Consequently, they are afraid to let me pull the plugs. They have no problem letting me have a mechanic do it, but the tires plus near them wants $230, and that just doesn't fly. The owner has repeatedly said he has no problem at all letting me have a mechanic look it over. I don't believe it was ever modded. However, they have been running it on 87 octane. Not really car people, not the types to have modded it and demodded it before sale. He has a lot of receipts for recent repairs, none of which he did himself. They car seems to be in excellent shape. It just gets under my skin, not being able to check the plugs. So, would the engine run like garbage with one or more bad pistons, or is it possible that it would not be noticeable, even under full throttle?
 


Yes, the engine would run like garbage with bad pistons...

If one got a tiny little chip, that managed to escape through the exhaust, then you'd probably never tell.


Best thing you can do is say "hey, im interested in the car, but I need to pull the spark plugs, or I'm going to walk away"

And if they say anything about it, explain that it's pulling spark plugs, you'll do 1 at a time, and they can watch to make sure you dont mess anything up.

If still no, tell them thank you very much, and good luck to them, then walk off.
 
Yes, the engine would run like garbage with bad pistons...

Hah, that couldnt be further from the truth. A chipped piston will still make good compression, and therefore run pretty decent.
 
Note. A bad piston. Then I went into explaining a chipped piston.

Reason I said a bad piston, is that's what the OP used, and I wanted to confirm that a bad piston (burnt, cracked, severly chipped, etc) will make the engine run terribly. But a chipped piston, you'd probably never be able to tell.
 
Life's getting interesting. The seller is completely willing to let a mechanic do it, but not me. He's worried that I may mess something up. Reasonable, I suppose. The problem is that the shop claims it will take 2.3 hours and want a couple of hundred dollars. They will do the front ones as part of an inspection, though. I almost think he'd let a mechanic tear it down to a short block if I paid.:th_winking:
 
I've had chipped piston motors run great on a fresh plug and quickly foul out and run seemingly one cylinder down. Aka..like garbage. Also seen them run w/o any symptoms. It seems to go either way, basically does the cylinder lose compression or is a piece still kicking around in the cylinder are the biggest variables.

Do you have a scanner or aeroforce? I'd see which cylinder is giving the problem and try to determine it that way.
 


I don't have any reason to believe anything is wrong with it. It's just that the owner told me they have put nothing but 87 in it and the woman driving it gets in the boost regularly. It seems to be completely stock, and it runs smoothly, but I still wonder about it.
 
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Running 87 makes the cars exhaust heat up more. It's not good on the motor or car. I'd walk away just knowing that.
 
Is this a woman/woman couple you're dealing with? What guy doesn't at least even understand the concept of a spark plug?
I said this on chat the other night. Too cheap to spend $4-$5 extra on a fill up = too cheap to have it maintained correctly.
I guess you'd blow their mind if you told them you wanted to do a compression test also.
 
It's a couple. She's the one who will only use 87, because "it's too expensive to use 93." On the other hand, there has been a good bit of work done to it and he has receipts for a lot of it. Things like having the maf and the water pump replaced. I guess it was running a little bit off, so they had it checked out and replaced the maf. While the pump was being replaced, the shop gave it an inspection, so there is a list of things they recommended. The only repair item is a tie rod end, which would also require an alignment. The tie rod isn't very bad. I didn't even notice it when I drove the car the other day. I get the feeling that they are incredibly ignorant of car related things, and also anal about them as only the uninformed can be.
The car appears to be in excellent shape. From a visual standpoint, they've taken great care of it. Anytime they thought something needed to be done, they had it taken care of. The problem is how you define "needs taken care of." To the automotively challenged, many things that I would call mandatory would instead be optional. Really, though, it's going to be that way with any car I look at. Very few cars are owned by people who will actually take complete and proper care of them. And that leads up to the problem with walking away. I probably would have quite a while ago, except that I need a car pretty quickly. Some guy totaled my durango, and I'm losing the rental soon. As much as I'd like to take my sweet time and shop until I find the perfect car, I just don't have that option. It's down to this car, with it's receipts and the "feel" for it's current owners who are using it as a DD right now, and another one without any of those things and it's farther away. The owner of this car has absolutely no problem letting me take it to a mechanic for an inspection. It's just that the idea of paying several hundred dollars for it isn't sitting well with me. And since it's a little ways away and I won't have any off days until after the rental is due back, and I don't know any mechanics down there, I'm really out of options.
I'm sure the car is fine. GM designed it to not die on 87, or they would have been replacing them every day under warranty. And even if I find out it's not suitable to mod, at least it would probably still be a good DD. It just that it's so irritating to be balked over something so simple. He's going to drive it over to the Tire Kingdom next to his house tomorrow to have it inspected again, and they have said they will check the front 3 plugs for me. He said he will take pictures of them and send them to me. Are they the actual plugs from the engine? I won't really know, since I'll be at work tomorrow when he goes there. Still, he has encouraged me to have it inspected and to be present for it. It's just not possible.
I'm sorry for the monologue. I'm tired from sleeping in the hospital the last 2 nights with my 8 year old daughter. She's fine, and home tonight. The thing is, I'm tired from not sleeping in there and very frustrated over the whole car chase thing. Every car except 2 that I've looked at have been immaculate inside and out and out and ran perfectly. At least in the ad. Then I get there and find out they've been wasting time that I just don't have, and I'm another step behind.
The really odd thing is that he's even willing to deliver it to me, half an hour away. I'd take that as total desperation to be rid of a hulk, except for the fact that he repeatedly encourages me to have it taken to a mechanic and inspected. He certainly doesn't SEEM to be hiding anything,
Oh, well. The bed is calling me, and I have to get up in a couple of hours to give my daughter a breathing treatment.
Have a good night everybody. I know I will. I'm gonna be in my own bed tonight.
 
OK, I'm back. Sorry for the whining at the end of my last post. It seems there are times when I just shouldn't be allowed to post. Anyhow, he took it to Tire Kingdom this morning and the plugs were all fine. Worn, which I fully expected, but no signs of detonation or problems of any kind. He's delivering it after work today, and I can hardly wait. :th_biggrin2: Pics soon. (Because I know you've never seen a black GTP before.)
 


Congrats on your new ride. I hope you will give it the 91-93 octane it deserves. It just makes me cringe seeing people put in 87 on a vehicle that's not designed to use it. I got a recall letter the other day and it clearly said that can cause engine fires due to the manifolds heating up more. I'm sure it didn't hurt anything her running 87 but knowing that would bother me and honestly its only gonna cost ya at most 2 bux more a fill up on average. Ugh people are ignorant. Can't wait to see your pics!
 
Re 93 octane- It's the first time I can remember wishing for worse gas mileage. I've got about 1/4 tank of 87 left, and I want it all gone before I refill with 93. Then I will reset the PCM by disconnecting it and the battery. Hopefully it runs a lot better then.
I'm thinking (hoping) GM made it pull more than enough timing to save the engine (at least when it's in good condition-carbon deposits causing hot spots would be asking too much) so they wouldn't be replacing engines every three days when people want to "save money" by getting worse mileage on 87 octane.
Pics soon. My next project is to deal with that cat that's been climbing on our vehicles. Pawprints show up REAL WELL on black. Little vermin.
 
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