E300 turbo,ultimate diesel or bad joke?
 

Here we go again folks! as some of you recall my '98 E300 turbo would exhibit disturbing symptoms when starting from cold,about a mile down the road I would lose power and dissolve in a cloud of white smoke but would eventuall overcome this and run well.
One day as mentioned in my previous posts it got to the point where Check engine light and engine electronics warning came on.

I bought a code reader,it told me the MAF sensor was bad,I replaced it with a new one,ran perfectly afterwards for one day,this morning on the second day it started acting up again,you guessed it,a mile from my house...........wife was pissed as she was late for work,talked about buying a new Toyota,this time I did not argue.

No codes this time,just like when it began doing this a year ago intermittently.

What am I missing,I got new O rings,prefilter,fuel return lines,no vacuum leaks,EGR is clean and works,any tricky relays that wouldn't throw a code?

Don't get me wrong,I love the car but I'm about ready to have a coronary over this overly complex nonsense.

There was another person exhibiting similar symptoms that turned out to be the pre-filter o-ring had not been installed correctly...certainly that is a very cheap fix, so why not try that first and see if it helps. Since it is sold separately from the filter many times it does not get replaced, but it should be!

Also, others have reported trouble with the K40 relay...more costly than the o-ring but not a wallet buster either...search under K40 to find other posts about it.

Good luck.

Well, I was very careful to S-L-O-W-L-Y twist the new pre-filter,with it's new viton {factory}ring in until it bottomed out,I also replaced the plastic fuel line on top of the pre-filter,new O rings came with it too.

I'll check it again but there was a good deal of resistance when I installed it which I took for a tight seal.

Went out and checked the new pre-filter again,O ring fit in well and didn't "ride"over the shoulder of it's groove,no problem there.

Would the K-40 {dealer part??}throw a code??

Carleton,
What you have described is EXACLTY what happend to me. The problem was the o-ring between the pre-filter and the aluminum block. A $0.38 part that cost me a few hundred of which most was the tow.

Understood,when I got the pre-filter from the dealer it CAME with a new viton ring,would I not see bubbles in the clear plastic line?

Quite possibly not. When mine quit, it coded for the glow plugs, which were not faulty. I opened mine up and resoldered all the connections to the circuit board, and it's been fine for some time.

Is the K-40 in the engine comp,or near the battery under the back seat?what does it look like?
Maybe I'll dig out my old Weller pistol-grip dual range soldering gun

I dont think you have air/fuel leak as it would need to be massive to cause the engine to die while running and should therefore make starting almost impossible.

It's in the module box, at the right rear of the engine compartment. Immediately ahead of the fresh air intake for the climate control. Four screws remove the cover, and the K-40 is at the front, with several fuses and several separate connectors with 3-5 wires each. You can't miss it.

You will need a gun for this soldering job, as there are rather large metal bars soldered to the board.

I don't know if it's a dealer-only part, but the local dealer wants $129 for the part for my '96 (which may indeed be different).

Carleton,
Just as an FYI from my experience this past summer when I first took my E300 to the shop I mentioned to the mechanic that some thought that it might be the K-40 relay. He told me that he would consider that as one of last possibilities as he said that he has only replaced a K-40 relay once and it happened to be on an E320. I tend to trust this dealer mechanic. He also told me that he uses this form site as well as his tech training to diagnose problems.

I hope you can find the source of the problem soon. I am beginning to think that on these E300's 95% of ant repair is trying to find the source of the problem.

P.S. I did buy a K-40 realy from Phil. It is not listed online. Just call. Now I have a relay.......just in case??

Thanks guys.

I'm leaning in the direction of a fuel leak or air sucking as 2 of the plastic lines going to the IP looked wet when I had the manifold off,$24.00 for new ones which come with the O rings,should be here tomorrow.

Odd how it only happens about a mile or 2 from a cold start.
Do these cars have a coolant temp sensor that feeds info to the computer like a Jetronic system?
I have read a good deal about weak solder joints on the K-40,besides I have a background in radio/tv repair so I'm not scared of it,wouldn't hurt to inspect it.

Just for kicks where do I access the tank filter screen just so I can see if it's black with dirt/algae?

For me what happened is that after setting for a while there an air gap formed at the prefilter. When I would start there was a continuous segment of fuel from the prefilter to the injectors. Around 1.5-2 miles the air gap from the leak at the pre filter worked through the IP. There was a small hesitation and then no problem. Mine quit when I backed it out of the garage and left it running. The car was on a slight downward slop the resulted in the tank setting lower. Because more suction was required to bring the fuel to the engine thus the leak ‘revealed’ itself as the fuel lines were sucked dry. You might try parking your car on a slope like this to see what happens. The mechanic told me that he has a fuel cap with an air fitting has he also uses to check for leaks. He uses just 5psi on this cap an any leaking o-ring will be noticed.

I don’t think that the W210 have an in-tank screen like the W123’s.

Now THAT'S what I call a point in the right direction,like an embolism,it's not immediate but when it occurrs it's devastating,I'll try what you suggest.

I CAN tell you that after the car sits there is a visible air space in the clear prefilter line,looks like fuel is running downwards thru the plasic line toward what appears to be some kind of fuel chamber hooked into the cooling system on the side of the engine.
You can see the air space in the pic,should it be full of fuel at all times?
http://i5.photobucket.com/albums/y183/stellite/line.jpg

Solder joints look cohesive,checked 'em with my jeweler's loupe,no loose connections,no"tracks",nothing visible,should I flux and solder'em again anyway?
What's the black relay box in the last pic for??

http://i5.photobucket.com/albums/y183/stellite/re1.jpghttp://i5.photobucket.com/albums/y183/stellite/re2.jpg
http://i5.photobucket.com/albums/y183/stellite/re3.jpg