Last post on Nov 29, 2013 at 2:06 PM
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BMW 3 Series, Sedan
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#5350 of 5378 bmw 325 engine failure
Aug 27, 2013 (10:54 am)
We have a 2004 325i. The last time when I drove it, the engine stalled on the road. Towed it to a mechanic (not a bmw expert). He replaced the coils, but which didn’t do any good. Then towed it to a bmw mechanic, who showed me low engine compression -- readings of 40 and 50 on a couple of the cylinders. He told me later that a couple of the valves were not closing, so, the cylinder head has to be replaced as there is no point to repair in a piecemeal fashion. The cost would be about $2500. The addition repair needed include the timing chain guides.
The car has only 125k miles. So it wasn’t driven harshly, but we did overlooked a couple of maintenance items, like spark plugs were not replaced until about 110k miles and the air filter was replaced late too.
Any advice for me for the diagnosis of cylinder head replacement? Thanks in advance.
#5351 of 5378 Re: bmw 325 engine failure [tlw6]
Aug 27, 2013 (11:24 am)
Was it running fine prior to stalling? What led guy #1 to think it was ignition? Not competent? If running good, what would all of a sudden cause the valves to not close? Was the oil level good? Lack of upper end lube could cause the valves to bind. In an interference engine, severe damage could occur if a timing belt were to break and the valves collided with a piston. Baaaaad news. Not consistent with ignition or coils. Opposite issue. I would want to know why he thinks the valves aren't closing. A compression test would show this. ALL cylinders? If just one or two, it could still run. I guess I would get another opinion and maybe look for a good shop that deals with foreign/European cars. There are good ones out there that won't rip you like a dealer. Ask around. For $2500, I would certainly get a couple more estimates. Hard to do when the car won't run, but describe the problem to them and see what you hear.
#5352 of 5378 Re: bmw 325 engine failure 
by kyfdx@Edmunds HOST
Aug 27, 2013 (4:03 pm)
If I read it correctly, the 2nd guy they took it to, is a BMW mechanic..
If he says it needs a new head, it probably does... (plus, he did a compression check)
Now, do you want to pay $2500 to fix a $7K car? Seems like you almost have to...
#5353 of 5378 Re: bmw 325 engine failure [tlw6]
Aug 27, 2013 (4:57 pm)
I dunno. Are you sure you are relaying the info right? "Not closing" and "40 and 50" psi on a couple of cylinders are very very different. That would be NO compression vs LOW compression.
#5354 of 5378 Re: bmw 325 engine failure 
Aug 27, 2013 (4:58 pm)
The first guy was incompetent. That was why I towed the car to the second shop, which deals with European cars. I am not very familiar with these issues, but saw him pulling a spark plug (closest to the radiator) out, hooked up his pressure gauge, showed me the readings of about 40 or 50, and said that the min. to get spark should be ~75. He did this for the next 2 cylinders, with similar readings. I assumed that he knew what he was doing and that must be the compression test. Is it?
But I don’t know whether the first guy had anything to do with these “low pressure.” This first guy wasn’t able to start the car, I believe, during the stay of the car in his shop. He also changed the thermostat b/c it was one of the shown codes.
Once in a while in its history, this car felt like the engine was slow and kind of struggling when first started. On average, it would also stall once every several months, but we could always restart it. But, for this last time, I just felt that the engine got slower and slower on the road and eventually stalled and would not start again.
In terms of the oil level, the low oil warning light always came up when the car first started, even right after an oil change. But the light always went away after we drove for 100 ft or so. The first mechanic (who I use for other family cars, Japanese) said that it should be an oil sensor issue and don’t worry about it. So I took his word for it. But now I begin to wonder whether the oil pressure has been low now that you asked about it. We do change oil regularly.
I just dug up my scribbly notes about what the second guy said after I left my car with him. He said that Valves #3 – #6 were not closing and the head gasket was blown. I will ask him what you asked “why he thinks the valves aren't closing” tomorrow. He also said to change the timing chain guides.
Any further inside with these additional descriptions? Really appreciate your opinions.
#5355 of 5378 Re: bmw 325 engine failure [qbrozen]
Aug 28, 2013 (7:47 am)
thanks for the reply, and it just showed my ignorance in these issues.
to try to clarify what I said, when the car was towed to the (second) mechanic, he checked the pressures on 2 (or 3) cylinders that are closest to the radiator and 40 or 50 psi were shown on the meter. I don't know how the cylinders are numbered. I would hope that those are #1 and #2.
when I called him after a few days, he said that "valves 3 – 6 are not closing." I don't know which are considered "#3" thru "#6." If #6 is closest to the radiator, then what he told me over the phone were not consistent with what I saw on his pressure gauge.
How are the valves numbered? thanks in advance again.
#5356 of 5378 Re: bmw 325 engine failure [tlw6]
Aug 29, 2013 (4:58 am)
Might be best to find a shop that specializes in BMW. This might mean going to a dealer. If you live anywhere near Silver Spring, MD, try the namesake dealer - BMW of Silver Spring.
#5357 of 5378 Re: bmw 325 engine failure [tlw6]
Aug 29, 2013 (5:20 am)
I can only think maybe he means they aren't seating properly. But, honestly, that's just an assumption based on a compression test. A bad head gasket or worn piston rings will also give low readings.
#5358 of 5378 Black Soot Exhaust
Aug 29, 2013 (1:42 pm)
My 2013 335i has very black soot at the exhaust tail pipes. The dealer service said its OK. They said if anything was wrong there would be indicators and codes for review. However they couldn't explain what is causing it. It doesn't look good to me and some of my friends noticed it and said it has a rich mixture and can damage the engine or catalytic converter.
I called BMW North America and I was told they only help with car features or personal issues and that I should go back to the dealer and have them check it out again. CATCH-22.
Is there anyone who can verify ond/or explain what causes this black soot. Do I need to go to the dealer and check all the 335 exhaust pipes to see what colors the exhaust is, than if they are different than mine I am back to where I started. I am concerned because I am planning a drive to Colorado to see my son and do some sight seeing. (see America trip).
#5359 of 5378 Weird Radio Issue
Sep 20, 2013 (12:40 pm)
I have a 2013 320i with a strange problem. This has happened 3 times so I have finally discovered the pattern but not the cause: our church parking lot is under some major power lines. You can actually hear them buzzing when you walk under them. When I park in a certain place in the lot the elevation puts my car within 50 feet or so of the lines and when I start the car the radio will have lost all of its station presets. After a restart or 2 they will return. Is something not shielded properly or is it just the proximity to the lines? Anybody else ever have a problem like this?