alero 2.4 1999

[eastern]

helle eveybody

beginning of the year i bought an alero 2.4 1999 ( 155000KM )soon after i bought it we had to replace the seal in the timing chain cover this al went well.

now i have another problem while driving sometimes the track off light will burn and the car will start driving in a emergency program what means the motor and automatic transmission will work but very bad.
the motor even stalls or almost stalls when you stop

when i turn off the engine and start again everything is ok untill it comes back.

The dealer read the fault code and that is tps sensor voltage low they told me they repaird a cable because is was damaged,

but now after 1 month it is back again with the same fault code.

one other thing is that when the engine runs idle the motor shakes , when you turn on the airconditioning it shakes less

what i did so far :

1 new sparkplugs ( delco from dealer )
2 new air filter
3 cleaned the tps sensor and the throttle valve
4 cleaned the valve that controls the idle
5 new motor oil and filter
6 new seal in timing chain cover
7 changed the serpentine belt
8 checked for vacuum leaks but did not find any
9 fluid levels are ok ( cooling / brakes / motor oil / power steering / transmission)

any one has any ideas what to do to make the shaking go away and how to repair the tps sensor voltage low
I dont know how to test the tps sensor but the light is only sometimes on and after stopping en starting the motor it is gone again for a while.:eek:

the dealer was shure it is not a wheelhub or abs related problem the scanner clearly says tps sensor voltage low

thank for the info , besides the small problems i like the car and it drives ok only it uses a little bit to much gas 1 liter on 9 km avarage ( driving half of the time in the city and the other half on the hiighway)

[[ion] C2]

Replace the TPS..... I mean clearly, LOL, that is the problem. It can cause some crazy shit to happen when it goes.

It's easy, two torx bolts on the side of the throttle body.

http://www.byunspeed.com/images/GM17123852.jpg

[leoalero]

welcome man,listen to him,hes a king for the LD9!!!!

[eastern]

ok thank i do it as soon as i find a place where i can get it easy ( dealer told me it can take op to 2 weeks to get it i live in the netherlands )

[undersc0re]

Just unplug the thing for now and see how it drives....

[[ion] C2]

No, replace it. By unplugging it you're just going to experience other issues and won't know what's causing what.

[eastern]

hello Back again,

I jus put on a new tps sensor 2 day ago , no more lights:yahoo:

but.......:(

The problem with the shaking stays ,

When i start the car and it idles you see the motor go back and forward , when you put the car in drive the whole car does the same shaking

If i turn on the AC it is a lot less but you can still feel it a little , the motor mounts are checked and are ok.

Where can i look next , tried to disconnect the iac valve but nothing happens is this normal or should the engine respond to disconnecting the iac.

[clutch1]

When i start the car and it idles you see the motor go back and forward , when you put the car in drive the whole car does the same shaking

If i turn on the AC it is a lot less but you can still feel it a little , the motor mounts are checked and are ok.



My friend has a 3100 that did this, same symptoms with the AC on and off and all that.. I'm curious now, too.

[[ion] C2]

What is it trying to idle at? When you engage the A/C the RPMs go up a bit. If the car is idling too low it will cause it to run rough.

[Toxin13]

I sometimes get the trac off light for no apparent reason, and I've heard a lot of things about wires near the wheel wells that get a little loose or shake affecting that and the brake light.

[colonel6632]

my cars trac off light used to go on when i went about 130... car would start shaking and then the light come one... balanced my wheels... doesn't do it anymore

[heineck]

could be an exhaust leak when i had mine the car shook like a mothereff

[clutch1]

could be an exhaust leak when i had mine the car shook like a mothereff

2 header bolts were sheared off on it.. that's prolly the 3100's issue, for sure.

[eastern]

helllo

the idle is around 800 but if to slow how can you get it higher.
this can be it because when i put a little bit of throttle it is much less or gone.

[AleroDrime]

I sometimes get the trac off light for no apparent reason, and I've heard a lot of things about wires near the wheel wells that get a little loose or shake affecting that and the brake light.

check the gas cap seal

[eastern]

hello

the car still shakes

1 checked gas cap seal
2 checked and cleanes iac again

but i still can not get it to stop , only solution is to keep ac all the time on then it is much less

[Blktrax]

Some thoughts on your problem...

When you had the Timing cover off, did you inspect the Timing Chain and the Tensioner. (#16 in the diagram below) If there is too much wear on the tensioner it can cause slack in the chain and the timing to be off. ANd experience problems like youre talking about. When added load is put on the engine it seems to go away. Depending onthe previous owner and the frequency of oil changes, the faster the tensioner wears since its nothign but a plastic guide and a metal chain.

http://www.trademotion.com/schematics/mechanical/NBP020.gif


Some other thoughts would be to do a compression test.

Also to check the ignition system, you may have a split plug boot or a coil thats starting to fail.

[eastern]

just a small addon , i can not believe it is the tensioner or faulty comperssion because the car does not shake every time but ithink it does it about 60% of the time will in drive and standing still

i think if it is one of the above it will shake all the time or am i wrong

regarding the coils should the car not give a fault code fot missfiring?

[Blktrax]

I have seen stranger things happen.

I'd start with the simpler stuff, such as the 2)ignition module, 4)coil, 10) plug contacts, or the 8)distribution block. <- Seen heat stress cracks that Arc to the head.

http://www.trademotion.com/schematics/D/DG99160.gif

But doing a compression test would be cost basicly nothing and tell you and overall health of the motor. Another posibility would be a vacuum leak. In regards to the check engine light, somethings obviously going on, but not enough of a range to set the light.

[meadus101]

Suck a Can of Seafoam into the Intake, it might not fix your problem, but the stuff is amazing.

[eastern]

hello

We just found the probem what might be the reason of the shaking , today one of the rod bearings gave up and it is ratteling now.

I was just lucky it happend when i stood still and i shut off the car the dealer tells me it is the bearing of the fourth piston.
He read the computer again but no faultcodes so he said that for now the engine itsef can be ok.

So we will remove the cartepan tonight maybe and see what the damage is if it can be repaired with a bearing we do it and maybe i trade in the car for another car.

the ast option is to scrap the car but i hope not we will see

[GA_turbo]

I was going to say that i could be a bent valve, a very slight bent valve can cause the same problem like you were describing ( shaking at idle and smoth over a 1000 to 1100 rpms )

[eastern]

:cry:

The motor is finished , the bearings are damaged but not broken but when we looked better and removed one is was clear.

the crank axel was eaten away , the bearing did not get oil , to repair it it means to replace the complete crank , pushrods and bearings.
There might be more damage because there are metal shavings in the oil.

So i sold the car for 600 euros and i am looking for something else and hope better luck next time :cry: :drunk: