Car shaking after valve job


#1

I had a valve job on my 2006 Bmw 750 li, when I picked the car up from the shop the engine was loud ,before the job it was quiet couldn’t tell the car was on , it also shakes back and forth while idling at every stop light,and when I take my foot off the gas the engine kind of jerks I have taking it back to the shop several times and they seem to not know what it could be they have recalibrated the valves and it seems to not shake soon after I leave but right when I’m a mile or so away it starts to shake again , does anyone know what could be causing this? I’m pxxxed I paid them close to 4000 to replace the valves and now the car is running rough. Help please I’m getting very impatient with them!


#2

Seems like the shop did a bad job and are incompetent to fix it. I’d take it to a dealer for an estimate and be prepared to take the first shop to court.


#3

@Lisalove
"I had a valve job on my 2006 Bmw 750 li…"

What more do you know about this?
Why would this particular 06 BMW need a valve job?
What were you told what could have caused it?
How many miles on this vehicle?
Who diagnosed this as the actual problem and how was it determined?
Was it the same shop that “repaired” it?
What were the symptoms before the “repair”?
Which symptoms are new ones?
Does this shop specialize in BMW or European cars?
CSA


#4

they have recalibrated the valves
It would be good to know what they actually did to “recalibrate” the valves.

From your description, I don’t have a lot of comfort in the work they did.


#5

I agree with Bill Russell that the way to go at this point is to take the car to either a BMW dealership or to a very well-reputed independent foreign car specialist. It is fairly obvious that the guys who did this “valve job” didn’t know what they were doing, and I fear that the engine is being damaged every time that it is run.

Be prepared to take the original shop to court.


#6

I had a diagnostic by bmw because of a oil leak and smoking while idling and was told the valves needed replaced, the car ran good other than the smoke, the shop I went to “specializes” in foreign and European cars and I was told it would take them 10 days to fix, they actually had the car for 4 weeks, seems like they waited on the heads to be returned every time I called to check the progress. They told me they hooked up their machine and it states the valves needed recalibration what ever machine that is, and mind you they have done this every time I take it back to them.The check engine light came on but went off right before I took it back to them and they told me they don’t know what the problem is and to wait unt the check engine light comes back on smh ,well it’s been 5 days since the light came on and I don’t believe it will come back on, I’m taking the car to the dealer again to get another diagnosis to get to the bottom of this. The reason I didn’t go with the dealer to fix this problem was because they were charging over 8k to fix I didn’t have the money to pay them. 160 k miles on the car.


#7

Lisa, if you get this car running properly - you might consider letting it go and getting another car. A 10 year old BMW is an expensive car to repair and at this age more repairs are in the future.


#8

"oil leak and smoking while idling"
Smoke caused by valves? Maybe they said worn valve guides or seals.

"they hooked up their machine and it states the valves needed recalibration"
Maybe they’re talking about valve timing.
Since they removed the head they could have botched re-installation of the timing belt/chain.


#9

“Since they removed the head they could have botched re-installation of the timing chain.”

I think that is the most likely scenario.


#10

OMG… Where do I begin? This is a DISASTER… Im so sorry to hear this story…


#11

I tend to agree with Honda Blackbird’s OMG…

There are too many unknowns on this. A valve job would be unusual except in the case of very high miles or damage due to a timing chain breakage.
The need for a valve job is easily determined by a compression test. Hopefully this valve job was not recommended solely on the basis of smoke.

At this point I would want to know 3 things.

  1. With 100% certainty that the cam timing and so on is correct.
    2.That engine compression is good.
  2. Did these guys even run a compression test at the start of all of this?

I believe this is an interference fit engine so if the timing chain was off it’s possible the engine could need another valve job…

I wonder if this entire debacle was due to a simple crankcase breather problem?


#12

The valves are a sort of traffic director inside the engine. They open to allow the air and gasoline into the engine, and open to allow the exhaust gasses out of the engine, and close to compress and explode the fuel and air mixture. So they’re pretty important to a smooth running engine. Something must be amiss with all that. This is what I’d check for

1* One or more valves may not be opening far enough. Check the valve clearances.
2* One or more may be opening too far, and not closing tightly. Again, check the valve clearances.
3* One or more valves may not be sealing correctly. Check the cylinder compression.
4* The valves may not be properly synchronized to the pistons. Check the valve timing.
5* Check for broken valve springs.


& as suggested above, in order to do a valve job lots of stuff has to be taken apart in the engine compartment and removed. For the engine to work correctly each and every bit has to be replaced exactly as it was before. This may seem daunting, but usually if something isn’t put back together correctly it will throw an engine diagnostic code, so can be easily discovered and corrected.

Ask your shop if they’d checked all items 1-5 above, and read out the diagnostic codes. Let us know what they say.


#13

IMO, the shop that did the valve job appears to be incompetent AND unwilling to make things right

Get that car out of there

I would tell them you’re taking the car and bringing it to another shop that is better able to diagnose and repair the problem. And tell them WHY. Also tell them once it’s diagnosed and repaired, they’ll be hearing from you again


#14

It is sort of odd they’d return the car to the customer with a symptom seemingly that obvious remaining. I guess it depends on how obvious the problem is. Sometimes it is more obvious to the car owner than to the shop I guess.


#15

The first shops screwed up. If it was my car & money, I would not put $4 in a BMW that age, but that ship has sailed.

You have to go and let the shop know that they have botched the job, you will go to the dealer, get an itemized list of what they did wrong and then go back to the shop and try to get a refund or even better have them pay for the repair. If it doesn’t work, you will have to take them to small claims court. Keep all your papers and get a log and document everything ASAP with date/time/names.

The only thing I don’t like is that you still have to spend more money to have the dealer fix this but then again, you can not sell the car the way it is.


#16

I will have to concur with @ok4450