Buying a car with a rough idle

[RawrImAMonster]

There is a 98 GSX for sell at my local dealer's auction. My uncle is a car dealer so this usually ends up being where my family gets most of their cars. Since this car is at an auction, I wont be able to drive it, but i did get to start it up and let it run a little.

First off there is some sort of exhaust leak, it was loud as hell.

Second, it idled really rough and would die out if you didn't give it gas to keep it running. This is mostly what I'm worried about. From searching I have gathered that rough idle usually isn't a big deal, but I want to make sure before I go buying this car. Are there any major problems that can cause a really rough idle?

I'm asking all this now because I don't want to get stuck with something thats going to fall apart as soon as I get it off the auction lot. Because with a car that has over 100k miles, there are absolutely no refunds.

That being said, I think I could pick this car up for around 2500. 98 with 133k body is in decent shape.

Thanks in advance for any help.

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What do you all think, is it worth it?

 

[TuRBoTaLooN]

There are two ways to go about this:

1) This is your ONLY way to get around. In this case, I'd be leary because the rough idle could be a number of issues ranging from minor inconvenience to huge headache. You don't know anything else about the car which means you leave yourself open to the possibility of breaking down on the way to work, on a date, etc.

2) You have other means of transportation. In this case, as long as the body and interior are in good condition, I'd definitely say go for it! The price is low and parts are cheap (most of them) to fix the car. I would definitely fix the exhaust leak, immediatley do a compression test, boost leak test and routine maintenance such as timing belt, oil, fluids, spark plugs and wires, and a general once over of the car. Check the BISS screw.

 

[SlickGSX]

Is that a Manheim auction? Why cant you test drive it if you put it back where you found it? Anyway, its a 10yr old DSM with a 7bolt that doesn't run right at a dealer auction, be prepared to spend some money on it. Either way $2500 is good for a 98GSX with decent body.

 

[illeffekt vr-4]

Is the BOV vented? Could be an easy fix such as a boost/vacuum leak but it could also be something more serious. Make sure you do a compression test and maybe even a leakdown test before you buy it.

 

[Novice]

The price is really great. You stand to still save money even after fixing it. But like the others say I would try to get as much time with it before committing to a purchase.

 

[RawrImAMonster]

Sorry that I forgot to say in my first post. The dsm would absolutely not be a daily driver, im just getting it for a weekend/project car. I know to do the basic maintenance once I do get one, i'm just asking whether or not you all think this rough idle is going to be a big deal or not.

Some things I forgot to mention:

The bov is recirculated.
The check engine light is on
I haven't driven the car but was told that it drives pretty good as long as you keep it above idle from my uncle

Some other things i noticed:

It looks like it has an aftermarket j pipe going from the turbo so i'm guessing that the turbo might be a 16g or something similar (again i can't really take stuff apart to look since its at an auction)
It has some sort of aftermarket clutch as the pedal is fairly stiff
It has hard upper intercooler piping


Again, I'm just worried that this rough idle thing is going to blow up in my face once i get the car off the lot. Thanks for the responses

 

[Artago]

If it's a 16G then check for fuel mods. If there aren't any then there is a chance that is was leaned out one too many times. If so, do a compression test. Check for crankwalk. Check engine light ... get a scan tool and read the codes.

Other than that, good luck and have fun.

Tomas

 

[stefanOst]

Does your uncle work at an actual dealership somewhere? If so, maybe he can borrow the obd-II scanner from a mechanic so you can take a look at what code it is throwing.

Like a few guys have already said, rough idle could be a serious problem or just in need of a clean air filter and new sparkplugs. My car idled kinda rough, but not too badly when I first got it, I changed the plugs to NGK and changed out the old air filter (literally caked brownish-gray in crap) and now it idles much better.

 

[RawrImAMonster]

I can't scan it between now and next wednesday, im not going to be around next week when its actually sold. This is why I have to make a decision to have my uncle bid on it or not before I leave on Friday. I *will not* be able to see the car again before its sold next week while I'm away.

As of now I have told him if he can get it for 2500 then go for it, otherwise leave it alone. I just don't want to get more money than the car is worth tied up in fixing its problems.

To the one of you saying that the rough idle could be a serious problem. What kind of serious problems are there that will cause a rough idle like that remember the check engine light is on as well. That could be related to the rough idle or it could be something else entirely.

Do you all think 2500 is a safe bid or what? The way I see it, even if the engine needs replacing, I can't really lose money if I were to have to sell it when I paid 2500 to start with.

Thank you to those of you who are helping.

 

[Jeff99GS]

Just buy it bro that thing looks nice for 2500... I bought My TSI and it idled rough like you are saying.... It turns out my Timing was off a tooth. So I re-did the timing belt and now the car is GREAT!

 

[strykout88]

I would definitely make the purchase, that is a really good price. Even if it is one of the bigger problems it still won't be extremely expensive. If you knew the codes it would be much easier. I had 2 codes for awhile and it ended up the my safc was bad. It could just be the base idle not being set correctly. Needs new plugs or wires, timing, vacuum leaks. The code could be unrelated being caused by the exhaust leak screwing with the sensor in your exhaust(really tired and can't remember the name), could be the isc, or even the tps. All of these problems are testable and fairly easy and inexpensive to fix. My advice is buy it and make sure you get a haynes manual and just start testing everything.

 

[crimsondragon]

It's probably not an exhaust leak making it loud. Try the aftermarket exhaust pipe.

 

[CRAIG___]

that is a steal u dont buy it i want it idc if i had to rebuild the whole motor 2500 is a steal get it

 

[toojung2die]

Do you all think 2500 is a safe bid or what? The way I see it, even if the engine needs replacing, I can't really lose money if I were to have to sell it when I paid 2500 to start with.

I wish I was buying my first DSM now. Even with the problems you listed I would probably buy the car. My car had a rough idle and numerous other problems I had to learn to fix and I paid over 3 times (5 years ago) what you say you can get this car for. I needed a new timing belt and tensioner to fix the rough idle. It was a tooth off. Could be your car's problem.
For comparison, I was looking at a GSX near me with a blown head gasket and a mechanics lien selling for $2K as an AWD donor car. Now I think I'll keep looking.
I will agree with what TuRBoTaLooN said though. You will probably need to spend lots of time and a few bucks to get this car into daily driver condition. You should have back up transportation until it's fixed. Good Luck.

 

[GSpikeX]

I would definetely go for it, come on 2500$ its looks good and like everyone said it could be as small as just adjusting the biss screw or bigger like an engine rebuild.. good luck either way.

 

[gregalmighty]

I'd buy that car in a heart beat. Buy it and dig into it and find out whats really wrong with it and then make your decision. If it turns out to be more work that you are willing to put into it all you would have to do is list it in the trader section and I guarantee someone takes it off your hands for at least what you paid. If it hasn't crankwalked yet at 133k then odds are it won't but even if it does have engine problems a rebuild is fairly simple and even better a 6 bolt swap wouldn't be too expensive even if you paid someone to do it. Either way keep us posted I'm interested in finding out how good of a deal you get and whats wrong with the car!

 

[xtr3me]

I noticed something like it looks like it had a front mount intercooler. So check to see if you even have a intercooler. I know it sounds retarted but, hey it could happen.

 

[->PrOjEcTGS<-]

Looks like the car already has some pretty decent mods. Maybe someone traded it in to get a new EVO or something just newer. There are some slim chances that it possibly had a 6bolt swapped into it. It could possibly have aftermarket cams creating the weird/rough idle. You know they've already done the clutch. If they went that far already don't rule it out as having more... I would pick it up. And if you can't figure out the rough idle you can always find a good used 6bolt and just drop it in and have a good cheap car!! BTW, looks like it has a good body to it. There is already some suspension work done, wheels, etc. Buy it, fix it, drive it. You are bound to spend money on it and as the saying goes "If your DSM isn't broke, YOU ARE!!" Get used to it!!

 

[RawrImAMonster]

It's probably not an exhaust leak making it loud. Try the aftermarket exhaust pipe.

Trust me its an exhaust leak. I'm just hoping it's past the turbo.

The stock sidemount is still there. One of the plastic pieces that goes inside the fender well was missing so you could see it up through there.


And to those of you that say it could be just that the timing belt is off a tooth. That would make sense because it says "new timing belt" on the window. The dealer or whoever had it before probably screwed it up. I wouldn't be surprised if it was the dealer because it also has "Eclipse Gs-t" written on the window. After seeing that I checked for a drive shaft just to be sure.


After your alls responses, I think I'm going to call my uncle up and tell him to offer up to 2700 outside of the auction. He knows the people who are selling it.

 

[Jeff99GS]

Yeah the timing being off is a common mistake...people will put the belt on with the gears lined up, but as you tension the belt the cam gears can move...The Intake will usually advance one tooth and the exhaust will retard One tooth. Thats how my car was when I bought it... idled terrible and had a P0505 Check engine light. I re-did the Timing belt and the car is fine now!!

I would pay like 4500 for that car

 

[->PrOjEcTGS<-]

I hate how 2g's get that gap between the hood and the bumper. You may want to do a VIN check on it just to see if it has been in any accidents previously.

 

[RawrImAMonster]

The hood was just popped, I hadn't shut it all the way after looking at it.

 

[dsm_Prince]

CARFAX the car and if it looks good BUY IT.

 

[RawrImAMonster]

I know the guy selling it wanted 3200 for it last week at the auction, but the highest bid was only 1600 due to the exhaust leak and the rough idle. My uncle offered 2200 at that point and the guy wouldn't take it. However, the car will be running through again this week and I'm thinking the guy will drop his expectations of price once he sees no one bidding higher on it again. That said, if he doesn't, I'm thinking I might offer as high as 2800 for the car.


A compiled list of the cars condition for simplicity's sake:

The Bad

Good paint except for the front bumper and hood which have a lot of paint chips

Rough idle with a check engine light (I'm guessing the timing is off 1 tooth at this point)

Exhaust leak

The alternator needs replacing

I don't like the wheels, but they are livable until they can be replaced.

*I don't know how the transmission is since I haven't gotten to drive it. It could be good or bad*


The Good

Again, the paint is in really good shape except for the front

It has a clean interior. Plus it has a nice tasteful greddy shift knob

The windows are already tinted to the amount of my liking

The clutch is already replaced with something that is pretty damn stiff. So this would likely hold up for a while. That is pretty valuable to me. I wasn't looking forward to doing a clutch install when that came to be necessary.

There is at least a 3" exhaust system installed. This saves me around 500 dollars for something I would have done anyways.

There is one of those big k&n air filters installed.

There is a J-pipe coming off the top of the turbo. This means its not a factory t-25 correct? I would say more than likely it is some sort of 16g. Either way, pretty much anything is an improvement over the t-25. It would be nice if someone could confirm or deny my thinking in this case. I'm pretty sure I've got it right, but not positive.

The car has a aftermarket stereo system installed. I didn't mess with it since the battery was dead (alternator was bad, see above)


Knowing all of this, does 2800 seem like a good price still. Should I be willing to go up to 3000? I really like the car, I just don't want to spend money on something like this and end up getting screwed.

 

[RawrImAMonster]

Ok, update time. I'm back from the beach and I got the car for 2400 flat.

I love it.

The transmission is fine. The paint is great except for the front bumper and hood which have paint chips. I'll probably have those painted eventually. The interior is near perfect.

Now to the problems:

The rough idle is still there, but it gets dramatically better when the car warms up. I'm not really sure what to make of it now. That doesn't seem like a timing issue to me since it nearly goes away when the car warms up.

I think the alternator needs to be replaced, I'll check that out tomorrow.

When I started the car earlier today there was a water leak. Now it seems to not be leaking near as much (there is definitely still water in it). I'm guessing the water pump is going bad, so I'll check that out tomorrow as well.

I'll post some pictures tommorrow once I claybar and wax it. Also, I'll give updates on the alternator and water pump.


Any ideas on that rough idle would be appreciated.