New injectors, need second opinion. (Video) - PeachParts Mercedes-Benz Forum

fred98050 · #1 05-06-2010, 10:24 PM

Just finished installing a rebuilt set of injectors on my 1980 300TD.

Not that the old ones were real bad but they were getting over 150k miles, from what I could figure out with the PO maintenance record.

I got a set of rebuilt with monark nozzle, 115 bar.
New heat shields and new hozes.

After the install, the I had quite a bit of smoke coming out of the exhaust, I could tell that it was fuel not oil.
Re-opened the injector's lines making sure that I had no air left in the system, no leaks anywhere. Still more smoke now that with the old set of injectors???

Don't know why, seems that the engine is louder than before..... Could very well be the paranoia setting in....

So here it is, engine noise with new set of injectors:
Does this sound normal to you?

http://www.youtube.com/watch?v=iWMcNVukC58

Thanks

vstech · #2 05-06-2010, 10:47 PM

no.
it sounds quite pingey.
did you rebuild yours, or get a new set?
i'd put in the old ones, and compare the videos

fred98050 · #3 05-06-2010, 11:19 PM

Quote:

Originally Posted by vstech

no.
it sounds quite pingey.
did you rebuild yours, or get a new set?
i'd put in the old ones, and compare the videos

I purchased a rebuilt set.

Actually, forgot about it but I had a previous recording of the engine after the last valve adjustment.

http://web.me.com/flangenard/Site/Before_after_valves_adjust.html

I'll check again tomorrow.

lvfast1 · #4 05-06-2010, 11:25 PM

Fred,
My experience when I rebuilt mine in my om603 the new monarchs I put seem to make the engine noticibly louder (nailing) across all the cylinders at first but within the first thousand miles (Daily Driver) it quieted down to a very even purr like I had never heard from the engine in my ownership. It had always nailed loudly in the #1 cylinder before. (Almost a out of rhythm knock). Hopefully yours will do the same (breaking in) maybe I dunno just food for thought. I was very worried at first in my case for no reason..

Arlo

79Mercy · #5 05-06-2010, 11:29 PM

It sounds fine in the video to me but you are right it is louder.

The FSM states that it will be louder for the first 300 miles until the newly rebuilt injectors "seat".

vstech · #6 05-06-2010, 11:29 PM

that is what i have heard as well. now that i think of it.
drive cautiously, for the next two fill ups, and see how it is then. and post another video like the first one.

KenB · #7 05-07-2010, 02:16 AM

If you want a set of German-made Bosch nozzles NOS, I've got and extra set. Just sayin'...

Diesel911 · #8 05-07-2010, 02:26 AM

How about the IP timing?
Members here have said a higher Pop/opening pressure = slightly later Timing.
If you combine that with late IP Timing due to Timing Chain/Gear wear it might make it sound off a little more.

I also noticed that when I advanced my timing past 26 degrees before TDC it nailed and I backed off some.
There could be a "Sweet Spot" as far as timing goes.

jbrianfoto · #9 05-07-2010, 07:29 AM

I also have an 80 300TD - I replaced the injectors last year (with a rebuilt set - forgot what brand) - your engine sounds exactly like mine. I don't recall there being any extra smoke though. I did have a problem with a few of the injectors weeping fuel around their mid sections. That went away after a few months.

fred98050 · #10 05-08-2010, 12:19 AM

First off, thank you all for your replies, I won't worry about the engine being a bit noisier than before for a while.

Cold morning here in the NW, some frost on the car this morning....

Car started fine, same as usual, little rough for 5 seconds that's all. Let it warm up for 20 minutes, some smoke at idle but not excessive. Now when taking off I noticed more smoky than usual for about 10 seconds then looked fine. Drove to town (5 miles) nothing unusual then went on the hwy for about 30 miles, got to 60mph or so, looked pretty good, no smoke noticeable.
Went downhill for about 2 miles and kept my speed at 60mph while transisioning to the uphill part.... Oh boy... I could see exhaust fumes (greyish smoke) pretty well.... Could not miss it.....

Smoke stopped when releasing the accelerator once on flat...

Went back home, let it sit at idle for about 5 minutes (no smoke) then shut off.

I decided to do a diesel purge and see what would happen. No smoke at all, which lets me believe that the smoke is fuel related not oil.(tell me if I am wrong)

So, here it is... Looks like when the engine is under heavy load I have a problem....

At this stage I have 2 options: One, is to reinstall my old injectors and see, 2 is take the car to a garage and see if the timing of the IP is ok....

Wondering if I should leave it like this for a little while and see if it improves... However, don't want to damage anything more than it already is....

I don't understand, why this would happen with new (rebuilt) injectors???? I would think that a better pressure and spray pattern would improve combustion.... Unless of course one or more "new" injectors are deffective.

Also, the car is equipped with an M pump, would this have anything to do with the smoke/new injectors problem?

What a mess....

Fred

Alastair · #11 05-08-2010, 07:19 AM

Left it warm-up for 20 MINUTES!!

Owners manual expressly advises against this!--Start up and drive away is what it recommends....

No wonder it smoked when you drove off after 20 mins idling!

fred98050 · #12 05-08-2010, 11:57 AM

Quote:

Originally Posted by Alastair

Left it warm-up for 20 MINUTES!!

Owners manual expressly advises against this!--Start up and drive away is what it recommends....

No wonder it smoked when you drove off after 20 mins idling!

That's what it took to defrost the windows at the morning.... About 1 to 2 minutes at high idle then another 15 minutes or so to get the windshield and windows defrosted. Might take too long to warm up.
Great, another thing to worry about....