Urgent!! trany rebuild - now engine problems???

[nariusb]

I had my tranny rebuild on my 1989 525i with m20 and 4hp22 transmision at AAMCO. The guy just called me and says tranny is in but the engine now sputters, doesn't idle well at all, stalls. Now they can't start it. They say I need a new cat converter?? The car was running great until I lost forward gears and the cat was not showing any signs of dying.
What did they do?? Please help.

[joshua43214]

Cat will not cause a no start. Its possible they broke it when they pulled the trans. In the auto repair world, trans installers are at the bottom of the food chain, some of these guys are real animals and places like AAMCO tend to get the worst of the lot.

Keep in mind, they probably dont have a single actual techinician on the payroll, they have a bunch of monkeys out front riping transmissions from cars, and some guys in the back rebuilding them at light speed. They have absolutley no clue how to diagnose an engine problem, but they will all fancy themselves mechanics and will be happy to tell you how to get the most from your 1968 Nova.

They broke it, they fix it. The car ran when you droped it off, it needs to run when you get it back. If they have to pay another shop to make it run, then thats what they have to do. I have had really horrible luck with AAMCO and I have had to repair some incredible butcher jobs they have done on trans installs.

Don't let them replace the exhaust, if you really do need a cat, you are better off at Midas than letting AAMCO replace it. Do not get nasty with them, just be firm abut wanting your car back running properly. They do have your car as a hostage afterall.

Most likely they forgot to plug something in.

[BigKriss]

ditto. Josh has made good points.

[genphreak]

ditto. Josh has made good points.

**** yea. I've met plenty in the trade like this. We're probably better about being nicer when we screw something up, but I have no doubt Australia is worse for the 'anyone can have a go approach' to technical tasks... make sure you make diary notes in case things get bad. You can always go and look over the car if they have it hostage, take a cam in your pocket so u can take pics of the work they have done if it is obviously screwed. The guys that fitted my exhaust broke the flexible joint on the manifold (literally) ripping the old one off. I had to go buy a new one for them. Due to their terrible workmanship Kriss and had to take it off again and and refit it on a weekend that we were doing the front end... manifold nuts were threaded on the studs, all sorts of stupidity on a simple bolt on job. What they did to my car was scary. Never take your Bimmer (or any car really) to a monkey shop, it's far too risky in my book. nick

[nariusb]

Thanks guys,
do you know if the computer has to be rebooted somehow to readapt to a replaced tranny? They said they were able to start it yesterday with difficulty.
But it doensn't start today. What could cause this? You say cat cant's be a problem of starting, why??
Thanks

[genphreak]

Thanks guys,
do you know if the computer has to be rebooted somehow to readapt to a replaced tranny? They said they were able to start it yesterday with difficulty. But it doensn't start today. What could cause this? You say cat cant's be a problem of starting, why?? Thanks

You don;t have to work it out, they screwed it up. If you tell them anything, it will be blamed as the cause when something else screws up. Beware and be firm as Joshua says. But I'd be noting it all jic I have to write letters to the local paper.

[BigKriss]

what model of e34 do you have? The cat is completely independent of the engine. You were saying the engine was running great before. I'm assuming they are saying there is a hole in the car - making the exhaust louder. To reboot the computer you disconnet the negative terminal of the battery for a while.

[Ross]

Get your car the F away from Aamco. These guys are Earl Scheib with a wrench!

[joshua43214]

Since aside from doing its job as an emissions part, all a cat does is route the exhaust to the muffler then out the tail pipe. Until the engine is running, you have no exhaust, so the car will start unless the cat is totaly blocked, which is not possible since it ran when you droped it off. If the cat is partialy blocked, the car will start and run with reduced power and possibly stall on decel. Partial blockage tends to get worse as the cat heats up, so the car would start, and run until the cat gets hot, then show signs of trouble. All of this is meaningless, since cats fail over time rather than instantly, so unless they somehow managed to melt the thing, there is no way that a car you drove in with good performance had a cat fail overnight as it sat on the floor.

[nariusb]

Ok, now the car iles like a kitten, they say, but at around 1500 rpm it goes , sputters, makes noizes.
I talked to Kirt and he suggested a cold reboot with battery cables disconnected and shorted for two hours.
Again it's a 1989 525i with m20 engine and ZF 4hp22 tranny. Is it cable driven or does it have a tranny computer?????

Get your car the F away from Aamco. These guys are Earl Scheib with a wrench!