w124 m104 need help again
 

i got everything bolted back together from a head gasket change..fill the fluids..start the car. runs and sounds like absolute ****. leaking coolant from somewhere on the back of the engine ..but not the heater hose, hooked up a vac guage its oscillating from 2-5hg. feels like its only running on 3 cylinders. idles at 800 and revs up pretty quick when you give it gas. no codes..no backfiring..no smoke

ill run a compression check but it kinda seems like i f-ed up my head gasket repair somehow. everything went together smoothly im a lil disappointed and a little bit frustrated

actually it looks like its only leaking from that o-ringed water line under the thermostat. so thats an easy fix.

Thanks for sharing?

check the coils for correct orientation1/6 2/5 3/4 has the correct way on the cover

I swapped them around with some spares I had. No change. Exhaust smells rich.


Was just asking for help/ ideas on how to fix my car

It almost sounded as if you solved with the last line "actually it looks like its only leaking from that o-ringed water line under the thermostat. so thats an easy fix. " but maybe not.

What would cause the back 3 cylinders to not fire? I started the engine cold and checked the exhaust ports for heat. Cylinders 4 5 6 are ice cold while 1 2 3 quickly heated up.

Perform a compression test before further diagnosis

Cylinder 6 has zero compression. Guess I need to do a leak down test now to figure out exactly what’s going on. Maybe a valve got damaged somehow?

How did you time? did you verify the positions of the cams with a 4mm pin flat against the head surface? crank at OT? intake sprocket turned CW?

Yup did everything. I’m 100 percent the timing is spot on. I checked.. rotated the engine double checked.. rotated a few times checked again. Variable Intake cam sprocket turned clockwise. I ran a shope inside and there’s no physical damage. Piston top is untouched.

Post the compression data of all 6 cyl with spark plugs removed. Obviously there is a mechanical fault (since 0 compression at cyl #6) I would get that sorted first.

Ok I’ll do that after work.

The only thing I can think of is that I put a lil bit of oil on the cylinder walls .. maybe it pooled on the piston and hydro locked or I had an issue with the exhaust cam being out of timing when I installed the head. I didn’t force anything. Maybe that was enough to bend a valve a little.

Head is off. Number 6 valves are bent a lil. Not fully seating.

what about cylinders 4,5 ?better check all of them, did you get a head gasket yet ? I may have 1 ill donate to your cause, im an mb tech was given about 4 104 gaskets from another engine guy that moved, im in L.A, just come pick it up im off Monday, I even have used valves if you need them

Number 4 and 5 appear to be ok. I’ll have the shop check everything. I was going to do a big pelican parts order next Friday. I probably could use those valves tho. The machine shop will definitely charge me a good penny for theirs. What part of la? It’ll be about a 2+ hour drive for me