1987 300D Sigh... - Page 3 - PeachParts Mercedes-Benz Forum

gsxr · #31 01-09-2011, 11:47 AM

A few comments in general:

1) Required reading for a new 1987 300D/TD owner is this article.

2a) The typical 603 head crack issue begins without major symptoms and CAN NOT be verified via compression test. The first symptom is pressure in the cooling system when cold, aka the 'squeeze the upper hose' test. If it's rock hard, you have problems. This only works on tight systems without leaks. Another symptom is if pressure is relieved (soft hose) and you do one quick WOT burst (say, 0-60 at full throttle) and the hose is suddenly rock hard, that's bad. A third symptom is abnormally high or fluctuating engine temps, i.e. 95-105C on cool days without major load (flat roads, etc); or if temp increases rapidly from ~85C to ~100C after one quick WOT burst. All these point to a minor cracking problem.

2b) When the head crack gets worse, symptoms become worse... exhaust gasses present in cooling system at idle, bubbling in coolant reservoir that varies with engine RPM, coolant loss with no external leaks (going out the tailpipe), white smoke, and finally - although rare - hydrolock. I've only heard of one confirmed case of hydrolock though, most people fix the problem before it gets that bad.

3) If you don't have any of the symptoms described above, the head & gasket are likely ok. Normal diagnosis would be to pop test the injectors and do a hot compression test, just to rule out problems with the bottom end and valvetrain. If those check out, the issue is almost certainly fuel delivery. My black 300D had a similar issue, it was also doing the "puff puff" noise out the exhaust with mild smoke and missing at idle. Injectors tested fine, compression was normal. I swapped in a known good IP and the problem vanished. I didn't think that an IP problem could cause symptoms like that, but I was wrong! Click here for a video of the misfire problem I had (warning - 38MB MPEG video).

4) I don't like your oscillating shutoff lever. It looks a lot like what Chris described in this thread, note that the solution was to remove and properly re-install the shutoff actuator. This would (well, should) not cause the misfire but I'd start by doing that first; it's relatively easy and costs nothing. Remove the ALDA (pictorial here) to get easier access to the bolts which hold down the shutoff pod. Before starting the car again, use a Mity-Vac to ensure the stop lever goes all the way down (horizontal) when vac is applied, and goes all the way up when vacuum is removed. There is risk of runaway engine if the pod is installed incorrectly, so it's always wise to test this prior to starting the engine.

dablk1 · #32 01-09-2011, 11:57 AM

good info

ngarover · #33 01-09-2011, 03:41 PM

Quote:

Originally Posted by gsxr

A few comments in general:

1) Required reading for a new 1987 300D/TD owner is this article.

2a) The typical 603 head crack issue begins without major symptoms and CAN NOT be verified via compression test. The first symptom is pressure in the cooling system when cold, aka the 'squeeze the upper hose' test. If it's rock hard, you have problems. This only works on tight systems without leaks. Another symptom is if pressure is relieved (soft hose) and you do one quick WOT burst (say, 0-60 at full throttle) and the hose is suddenly rock hard, that's bad. A third symptom is abnormally high or fluctuating engine temps, i.e. 95-105C on cool days without major load (flat roads, etc); or if temp increases rapidly from ~85C to ~100C after one quick WOT burst. All these point to a minor cracking problem.

2b) When the head crack gets worse, symptoms become worse... exhaust gasses present in cooling system at idle, bubbling in coolant reservoir that varies with engine RPM, coolant loss with no external leaks (going out the tailpipe), white smoke, and finally - although rare - hydrolock. I've only heard of one confirmed case of hydrolock though, most people fix the problem before it gets that bad.

3) If you don't have any of the symptoms described above, the head & gasket are likely ok. Normal diagnosis would be to pop test the injectors and do a hot compression test, just to rule out problems with the bottom end and valvetrain. If those check out, the issue is almost certainly fuel delivery. My black 300D had a similar issue, it was also doing the "puff puff" noise out the exhaust with mild smoke and missing at idle. Injectors tested fine, compression was normal. I swapped in a known good IP and the problem vanished. I didn't think that an IP problem could cause symptoms like that, but I was wrong! Click here for a video of the misfire problem I had (warning - 38MB MPEG video).

4) I don't like your oscillating shutoff lever. It looks a lot like what Chris described in this thread, note that the solution was to remove and properly re-install the shutoff actuator. This would (well, should) not cause the misfire but I'd start by doing that first; it's relatively easy and costs nothing. Remove the ALDA (pictorial here) to get easier access to the bolts which hold down the shutoff pod. Before starting the car again, use a Mity-Vac to ensure the stop lever goes all the way down (horizontal) when vac is applied, and goes all the way up when vacuum is removed. There is risk of runaway engine if the pod is installed incorrectly, so it's always wise to test this prior to starting the engine.

Great info, I'll work on it tomorrow when I get the injectors back in. I have a new mighty vac sitting here I have yet to open also and, my ALDA is already off...

ngarover · #34 01-14-2011, 09:35 PM

BTW, I have not forgotten about this thread. Due to the snow in N Georgia everything has been shut down, including the place that's going to test my injectors. He should be testing them Monday.

winmutt · #35 01-14-2011, 11:49 PM

Hey, I made it to work every day!

vstech · #36 01-14-2011, 11:53 PM

I hear you guys got hammered a tad more than we did in charlotte... I missed work on tuesday. the ice storm on top of the 6" snowfall that DID NOT GET PLOWED was just too unsafe for me to chance a 30 mile trek... I did drive wife into work with chains on the back without issues, but it's only 2 miles...

rscurtis · #37 01-15-2011, 08:36 PM

IMO, that's a decent looking car, and the clock still works as a bonus. I would fix it. I think you have a compression problem in one cylinder, and the unburned fuel is just being pumped into the exhaust, there is your smoke. If you had just a bad injector, then loosening the fitting to that cylinder would make a difference, it doesn't. It will make a difference in the smoke if you wait long enough and bathe the engine in fuel.

Secure the manual stop lever in the "off" position, and crank the engine. If it cranks unevenly, one cylinder has low or no compression. If it doesn't, then you could have an intake valve problem as others have suggested. This will enable a little troubleshooting without even getting your hands dirty.

ngarover · #38 01-17-2011, 12:20 PM

Quote:

Originally Posted by rscurtis

IMO, that's a decent looking car, and the clock still works as a bonus. I would fix it. I think you have a compression problem in one cylinder, and the unburned fuel is just being pumped into the exhaust, there is your smoke. If you had just a bad injector, then loosening the fitting to that cylinder would make a difference, it doesn't. It will make a difference in the smoke if you wait long enough and bathe the engine in fuel.

Secure the manual stop lever in the "off" position, and crank the engine. If it cranks unevenly, one cylinder has low or no compression. If it doesn't, then you could have an intake valve problem as others have suggested. This will enable a little troubleshooting without even getting your hands dirty.

The place has the injectors right now, and I should be hearing the news this afternoon. At least I'll know for sure if that an issue or not. I agree the car is worth fixing, there are to many new parts on it and the body is in too good of condition to part it out at this point. I would be willing to spend another 1500 bucks total on it to get it to be a good running driving car again. (which basically would put me into a total of 3k that I have into the car.

I have found rust. on both front shock towers. It had been overlooked before but was found while installing the new upper shock mounts. Looks to be a pretty easy repair though, something I would have the body shop take care of when I get it repainted (after I get it mechanically right).

Other than that rust, the rest of the car looks ok.

This week I plan on getting whatever part I need (head, IP etc) to fix this engine, plus a replacement water pump to fix that issue.

I showed my diesel mechanic GSXR's post about the head, and the test for it, and we are going to run them as soon as I get the engine running again.

So, here I sit, waiting on the news of the first tests...

bustedbenz · #39 01-17-2011, 12:58 PM

I went to pull-a-part and brought home an entire parts engine, 603.961 with a previously installed #21 head, whole thing fan to flywheel and crossover pipe to oil pan was $150 or so. Total job of putting that head on my block when my old head cracked: less than $600. All DIY.

ngarover · #40 01-17-2011, 01:04 PM

Quote:

Originally Posted by bustedbenz

I went to pull-a-part and brought home an entire parts engine, 603.961 with a previously installed #21 head, whole thing fan to flywheel and crossover pipe to oil pan was $150 or so. Total job of putting that head on my block when my old head cracked: less than $600. All DIY.

I'm hoping to get as lucky, we don't have any pull your own type places around here so I'm SOL in that sense.

Ether · #41 01-17-2011, 01:13 PM

Quote:

Originally Posted by ngarover

I'm hoping to get as lucky, we don't have any pull your own type places around here so I'm SOL in that sense.

Plenty of Pull a Parts down here in Atlanta. Not that far of a drive is it?

ngarover · #42 01-17-2011, 01:22 PM

Quote:

Originally Posted by Ether

Plenty of Pull a Parts down here in Atlanta. Not that far of a drive is it?

About 2 hours from me. I would make the trip if they had what I needed.

Ok, so I just got the call on my injectors, They all tested 100% fine. So, I'll go and get them and put them back in so I can get it down to the shop for the next step.

winmutt · #43 01-17-2011, 01:24 PM

Quote:

Originally Posted by bustedbenz

I went to pull-a-part and brought home an entire parts engine, 603.961 with a previously installed #21 head, whole thing fan to flywheel and crossover pipe to oil pan was $150 or so. Total job of putting that head on my block when my old head cracked: less than $600. All DIY.

Congrats!

2hrs is a long drive to go home empty handed. I've complained over and over to pullapart that they dont differentiate between chassis or fuel types....

babymog · #44 01-17-2011, 02:15 PM

I've only seen one 603 in three self-serve junkyards I frequent in the area, in the past 3 years. Also, the price at these (LKQ) yards is something like $260, plus core charges, and I'm not sure that everything is included for that. Regardless, if I had a pickup truck, knew of a good 603 (or 606) in a yard, I'd find a way to get an engine that cheap, I have had to buy the whole car for the last two engines.

ngarover · #45 01-22-2011, 03:56 PM

Got the injectors back in today, topped of the coolant and fired it up. Ran good. then seemed to do that miss again.. revved it up to 4-5k and held it for a bit, let off and it wasn't missing. Took it for a drive down the road. Punched it 0-60, 4 times, wound it up tight each time, you could really hear that turbo singing. Watched the heat the whole time.

out the pipe it looks like a good amount of grey smoke, cleared up more on each pass. Temp got to about the 3/4 mark so I backed it down and brought it home. temp fell to normal operating in the 2000 feet. Punched it up my little hill to my driveway and temp raised again, parked it, and the temp fell to normal letting it sit there and idle.

Then is started to miss again.

I did not have enough of the braided hose used for the return lines on the injectors, so I used some clear line for a mower. I thought I would see them fill up with fuel, but really only one injector had any over flow that I could see, #4. even then it was only a small amount on each side.

The stop lever does bounce a little, Holding it up does not make any difference.

My plan, I'm going to order the new water pump and figure out how to install it. (I have the instructions, but not the "special tools") Once that's on and I know the system is not leaking anymore I can test further.

In the meantime I'll go ahead and remove and properly re-install the shutoff actuator. See if that takes care of the jumping stop lever.