Fuel shutoff at 4500 RPM, why?

[skier LGT]

Hi guys, new member here, although I've been reading up a ton on here lately as I have been looking for an LGT for a few weeks now. Just bought an 05 LGT 5EAT yesterday, and am picking it up in a few days! Anyways, the previous owner says it needs a new intercooler because it shuts the fuel off between 4500-4800 rpm. The check engine light comes on and he says it goes away when the car shuts off and resets. I've read that the valet mode can limit rpm, but I wouldn't think the check engine would come on in that case. Tried the search bar, but clearly need to figure that out better. If anyone has had similar problems or can provide insight, that would be great! Thanks all! If someone knows another thread where this has already been discussed, that would be greatly appreciated as well.

[hadvw]

Run away, run away! Get your money back if you can.

 

There are lots of POTENTIAL gremlins on these cars - the most common being a dying turbo that takes out your engine. I have no idea what this particular issue means. Could be a serious boost leak that's making the engine run super rich/lean/knock, and so the ECU shuts it down? Could also be a failed ring landing (very common on these cars) causing lots of knock and going into limp mode. Could also be a vacuum leak to the FPR, which means it isn't getting a good signal after 4500 rpm. Or a host of other issues.

 

Unless you're happy and good to spend $6k next month on a short block rebuild, I would really recommend AGAINST buying this car.

[skier LGT]

Really? I got to test drive it the other day and everything else ran smoothly, no bad sounds from the engine and nothing I could feel wrong while driving it. I had my mechanic take it for a drive and do a full inspection on it, and he said it was sound other than the u joints have some play, so the drive shaft needs to be replaced as well. The previous owner said he has been driving it like this for a year and hasn't had any problems, just keeps it under 4500 rpm (which obviously isn't ideal, these cars are made for fun above that range!). I sure hope it doesn't take that kind of money to fix this problem.

[Andy_Mac]

Kinda suprised your mechanic didn't pick up on the 4500 limp mode look into it further before giving it the all clear.

Did the old owner give any indication why he thought a new intercooler was the all resolving solution?

[skier LGT]

He said it had a crack in it, so that would seem like it obviously needs to be replaced, but I'm not sure if that will fix the problem.

[skier LGT]

Also, he had a new OEM turbo put in at 100k, it's currently at 144k.

[hadvw]

I'm not saying it's a guaranteed $6k fix. That's the worst case, more or less. However, due to the turbo, etc, it's a little easier to get to that worst case than some other cars. I'm just saying - be wary - you MIGHT be in over your head.

 

Now, there's no denying that the OEM intercooler isn't great, and has issues - I have BarManBean's "bulletproof" kit on mine - search for that - and a grimmspeed aftermarket TMIC. You can often pick up a used OEM intercooler on here for $50 or so. I would say, if possible, get your $$ back and only buy it after you try another intercooler and that problem is fixed. Rev it to 6k a few times, in 1st, 2nd, etc and see if it still does it. Then pull the codes, if any. I think the '05 has a built-in code reader - search for that too.

 

The car might just have a simple problem - but this board seems to have at least one new user per month these days "just bought a new LGT, it has this one problem: ...." that ends up needing a new shortblock.

 

Edit: see this thread, for example: http://legacygt.com/forums/showthread.php/2009-specb-first-rebuild-257635.html?t=257635