Hello everyone!
i have a 1985 500SEL with 204,000mi. al lot has been done to it
because i love this car and want to keep it for a while. my last job
was to replace the timing chain with new guides and and to do a valve
job. i have a professional mechanic who only works with mercedes to
hepl me and he does.
after replacing the the timing chain, when we started the car, it was
shaking soooo bad. when we looked at the econo guage, it is obvious
that it is a vacuum leakit was arounf 3/4 away from its normal
position while idling. could not figure out the problem. this car
has all new vacuum lines with switches.
with this in mind, we also did a valvejob (sent it to a machine shop)
hoping everything is done properly. after replacing new gudes, seals,
rocker arms, headgaskets, intake was sent out to clean, new intake
gaskets, intake plenum gaskets, used air meter, new fuel distributer
o ring, all new air hoses and fuel injector seals and holders, new
throttle body switch.....WHEN THE CAR STARTED, SHE IS EVEN WORSE.
CANT UNDERSTAND WHY. ECONO GUAGE IS NOW AT 1/2 POINT WHEN ENGINE IS
IDLING.
please help. what are we missing here? has anyone else had the same
problem? could this be due to bad fuel pressure regulators? my
mechanic said he has to plug it in to a scope to further understand
the problem.
thank you in advance
Lushan
Kenneth P. Stox - 27 Sep 2004 16:36 GMT
Are you sure the valve timing is correct?
Lushan - 28 Sep 2004 01:10 GMT
> Are you sure the valve timing is correct?
Kenneth,
timing is positioned to Top Dead Center 0|0 mark on the harmonic
balancer. The left and right cam timing marks aligned perfectly. i
had separated the airmeter to clean (rubber air guide) and inspect for
any cracks or leaks. when i re-assembled, i did not use any sealer.
would that be an issue? thank you Kenneth!
Lushan
Tiger - 28 Sep 2004 03:21 GMT
You can find vacuum or air leak by spraying carburator cleaner at suspected
joints.
T.G. Lambach - 27 Sep 2004 20:30 GMT
Suggest you check the valve timing. A cam could be "off" by one tooth on
its sprocket - more than that and your shiny new valves might start
hitting the pistons!
VCopelan - 27 Sep 2004 20:57 GMT
>"T.G. Lambach" tlambach@NoHamOrSpamcomcast.net Writes:
>Suggest you check the valve timing. A cam could be "off" by one tooth on
>its sprocket - more than that and your shiny new valves might start
>hitting the pistons!
Or he may have the correct valve timing but he skipped a tooth or more on the
injection pump timing sprocket. He won't damage a valve but the car won't run.
T.G. Lambach - 28 Sep 2004 01:15 GMT
Oh, I didn't know that 5.0L gas engines used a chain driven injection
pump. Learn something new every day.
Paul - 28 Sep 2004 12:46 GMT
A few thoughts:
1. Check compression.
2. Check Ignition timing. This engine is timed by the dist and could get
off when doing the chain.
3. Did you run the engine long enough for the "hydrolic lifters" to adjust?
This could take some time. (several min)
4. Check for vacumn leaks with carb cleaner. Also the carb cleaner can tell
you if the engine is lean or rich. When sprayed in the intake, if it speeds
up, it is lean. If it slows down, it is rich. Spray just a short shot, it
doesn't take much.
Keep us informed.
Paul McKechnie
84 500SEL
> Hello everyone!
>
[quoted text clipped - 26 lines]
> thank you in advance
> Lushan
Lushan - 28 Sep 2004 20:29 GMT
Paul, thank you soo much
since the new chain, i remember my mechanic taking off the plug
wires. just put it in without checking the firing order. could that
be an issue? could it cause the econogugae to show at 1/2 point?
thanks
Lushan
> A few thoughts:
> 1. Check compression.
[quoted text clipped - 42 lines]
> > thank you in advance
> > Lushan
Paul - 28 Sep 2004 22:41 GMT
Yes it can be an issue and cause the guage to read at the 1/2 point.
On the 85 and older, the timing is handeled by the dist and it must be
adjusted correctly. On the 86 and later cars the timing is handeled by the
Ignition control moduel. Just use a standard timing light and set the
timing to 0 deg . Later you can advance the timing a little for better
performance and mileage.I run my 84 500SEL at 10 deg BTDC. Also make sure
the ign wires are installed correctly. I don't remember the firing order
right off but I'm sure some else knows off the top of their head.
Good Luck
Paul McKechnie
84 500SEL
> Paul, thank you soo much
> since the new chain, i remember my mechanic taking off the plug
[quoted text clipped - 50 lines]
> > > thank you in advance
> > > Lushan
Martin Joseph - 29 Sep 2004 08:03 GMT
> Paul, thank you soo much
> since the new chain, i remember my mechanic taking off the plug
> wires. just put it in without checking the firing order. could that
> be an issue? could it cause the econogugae to show at 1/2 point?
Um, Yeah
If the wires are not on the right order that is your problem for sure...
Marty
Lushan - 29 Sep 2004 21:27 GMT
YES!!!!!
it worked! it was the wires. i got the proper firing order right off
the valve cover. i cant remember the order but on the distributer, 2
wires were in the wrong position.....im soooo happy. thanks again for
all of your advice and help. we live to learn.
Lushan
> > Paul, thank you soo much
> > since the new chain, i remember my mechanic taking off the plug
[quoted text clipped - 6 lines]
>
> Marty