HELP my car!

[Deetow]

Hey all,

I just replaced the timing chain tensioner in my m42 by first expanding it using what I assume is the proper method. I also did the plugs. The car ran fine for 10 mins but halfway home it starting running rough and was low on power. I barely made it home.

Weird thing is there is no CEL or weird smoke coming out of the end.
Also when I rev pas 4000 it seems to sort out.

I'm kinda freaking out here and am scared to drive to work tomorrow.
Any help is appreciated.

So far I've checked the torque on the plugs. Should I pull them and the tensioner?

Chris

[Deetow]

Plugs are new too. They're Bosch fgr7dqp pluses. So far none are cracked. Going to try testing all for a spark next.

[DIY]

see what you should have done is pulled the engine to changie the timing belt ... then just scrapped it and got a real engine ... likea m20

I'm also using those plugs currently so I dont think thats the problem

maybe the coil took a dump?
did a vaccume line come loose after reassembly?
did the chain jump a tooth? if its just one tooth it may be better at some RPM and worse at others.. if you could check the timing that would clear that thought

sorry man thats all I can think of
and no worries its a M42 isnt it normal to be driving it past 4000 rpm :p

[DIY]

worst case sonario its a 50$ replacement aparently lol
http://maxbimmer.com/forums/showthread.php?t=148563

[egye30]

does it fire right up or is it hesitating? and if it fires up, how does it idle?

[Deetow]

Originally Posted by egye30

does it fire right up or is it hesitating? and if it fires up, how does it idle?

It fires right up every time without any problems. Then idles like shit. It will surge from ~600 rpm to 1000 rpm and shake a lot even at 1000rpm. Looking at the engine it's wobbling like something is unbalanced in it.

Sometimes it will calm down and idle at 850 and the shaking will stop but as soon as you touch the throttle the rough running continues.

I've checked for vacuum leaks and it's all clear. Tonight ill put the old plugs back in and see where that gets me.

Is is possible that the chain jumped a tooth before the chain tensioner filled up with oil?


Chris

[Deetow]

Originally Posted by DIY

worst case sonario its a 50$ replacement aparently lol
http://maxbimmer.com/forums/showthread.php?t=148563

Alright Mikey but you're helping with the swap, smartass.

[MaxBell]

Sounds like your ICV is not plugged in properly. If it starts but idles loapy, I'd check vacuum lines.

[E30M42cab]

I'd like to hear what you assumed was the proper method of expanding the chain tensioner.

I'm also curious if you removed the "nipple" from the ends of the new plugs. The nipples should be removed, and run just with the threaded ends exposed, otherwise the stems off the coils won't make contact correctly.

[mr ilia]

Sounds like spark plugs to me. Put old plugs back and see if things have returned to normal.
Check plugs elecrode gap and loose plug wires. Should be something minor, since it seems it was running ok before you did stuff to it.

Triple check your work...also does engine make diesel noise, like cluttering and banging noise when running? If not, then your tentioner is ok and I would concentrate on the plugs and plugs and plug wires.

Edit: m20 is a crappy old engine, that is only good for exhaust sound.

[Deetow]

Originally Posted by mr ilia

Sounds like spark plugs to me. Put old plugs back and see if things have returned to normal.

Edit: m20 is a crappy old engine, that is only good for exhaust sound.

It was this. the plug i installed in cylinder #2 was firing but i guess the spark was poor quality. I pulled them again after work and noticed that 1,3 & 4 all had some carbon deposits (she's running a bit rich) and #2 was clean.

I threw the old plugs back it and she's running great.

Thanks for the help.

P.S. What i assumed was the correct way to install the tensioner was to remove the old one. Uncompress the new one so it is at it's final length then muscle it back in and reinstall the cap. I've read of people installing it in its compressed state because its easier then reving the engine until it somehow uncompresses. IMO that's a stupid way of doing it and you're asking for timing issues down the road.

Chris

[Ceeker]

P.S. What i assumed was the correct way to install the tensioner was to remove the old one. Uncompress the new one so it is at it's final length then muscle it back in and reinstall the cap. I've read of people installing it in its compressed state because its easier then reving the engine until it somehow uncompresses. IMO that's a stupid way of doing it and you're asking for timing issues down the road.

Chris[/quote]

you stand corrected: :-)

To install, slide the compressed tensioner into the cylinder block with the piston end facing inward. Use a new compression washer and torque to 40 Nm. The final step in the installation procedure calls for revving the engine to 3500 rpm for 20 seconds. As this is done, the chain noise will be heard to decrease suddenly as the compressed spring is released and the tensioner is filled and expanded by the engine oil. (The compressed tensioner is released by the chain as it slaps against the chain guide during the revving process.)
Replacement of the tensioner is a simple fix that eliminates one possible source of engine noise.