run away diesel after bad shutoff valve install, she is not dead but hurt! - Page 2 - PeachParts Mercedes-Benz Forum

Jditom · #16 05-25-2011, 03:33 PM

I did call Metric Motors to get there take on it.
They see several a year from shutoff valve instillation

They see cracked heads, head gaskets blown or rings suffer from a run away do to rapid high heat and the theromstate does not have enough time to open!!!!!

Now that I really know how it works it is very easy install and I would have no problem doing this again the right way.

IP arm in front of shutoff valve toward engine (not in the arm). Push on shut off switch on the linkage and it should work fine. Put vacuum on the shutoff valve and you should see it work. If it's rough or stuck you did it wrong. Be ready for the worst case and another person ready with a block of wood to kill the air intake. Make sure eveything is out of the way in order to get that wood over the intake ASAP. You dont want to be moving things out of the way when this thing is at WOT

Scarry as hell

Jditom · #17 05-30-2011, 02:19 PM

Follow up bad news.

Valve adjustment = all intakes were too tight and all exhaust were to loose.
After that it started right up, still idles rough and smokes more than before.
But drivable with normal temp and oil pressure. Has less power.

Makes a noise, air leak? Pulse comes from the air intake

Compression test: Wet = with a squirt of oil and crank a few time before compression test.

warm/dry, warm/wet, cold
1 240
2 180, 140, 160
3 315
4 200, 220, 180
5 340

My take is valves/head needs help especially intake valves.

BIG question.

Should I redo the head or not chance it and do a complete engine.
Now this is not my daily driver and it has 164,000 miles and I plan on doing a complete restoration. Did not plan on doing it all at once

Thanks all

Jditom · #18 05-30-2011, 03:03 PM

Here is the video!

http://www.youtube.com/watch?v=RISCiXMM3BI

barry123400 · #19 05-30-2011, 03:13 PM

Well do a leakdown test or just air injection to verify what shape those intake and exhaust valves are in. You can compare all the others against the best cylinder.

The compression readings you got are pretty bad for an engine with just those claimed miles on it. If you remove your oil filler cap how much blowby is present?

Jditom · #20 05-30-2011, 05:14 PM

Should engine be warm for the blow by test?

barry123400 · #21 05-30-2011, 06:55 PM

Quote:

Originally Posted by Jditom

Should engine be warm for the blow by test?

Yes but I would also have a look at blowby before warmed up as well. One thing to keep in mind is I believe the engne can stand more than normal revolutions.

The speed limiting incorporated in the injection pump is to protect the pump I always read. Although the rotating mass is so small compared to the engine I am not sure how this makes sense.

Codifex Maximus · #22 05-30-2011, 07:22 PM

Sounds to me like a messed up valve either not sealing or not adjusted correctly. Did you do compression test prior to adjusting the valves? If so, how do they compare?

Jditom · #23 05-30-2011, 07:47 PM

It was very hard to start so I started with the valve adj.
There is no speed/rpm limiter when you are pushing on the IP arm.
So it was WOT.

Yes valves are no doubt messed up. Just wonder if piston rings are too.
According to the wet test they seem OK.

I will probably do a leak down test later this week.

Jditom · #24 06-01-2011, 01:08 AM

Blow by test with engine warm is below.
I also did it cold and there was almost no blow by.

http://www.youtube.com/watch?v=pTi9m9rNJLE

barry123400 · #25 06-01-2011, 03:16 AM

That does not look too bad at all in my opinion. I would now seriously try to prove the valves have an issue or there is another problem in the head.

Its possible that some of the compression rings were damaged. I just doubt it by the indicated lack of blowby or pulsing/puffing of it. This is almost reduced to a gambling type situation with the odds favoring those valves in my opinion.

Remember that I am far from an expert and what I think are only my opinions.

Maxbumpo · #26 06-01-2011, 07:51 AM

For future readers: When replacing the vacuum shut off valve, once you think you have it hooked to the fuel rack, and before you replace the screws, try applying vacuum. If the valve pulls itself against the injection pump when vacuum is applied (your mouth is a fine vacuum source for this test), you can proceed with confidence. If the valve does not pull, you've missed the hook and will have a run-away engine if you tighten it down at this point.