I just got my new head installed (about time huh). All seemed to be going well.....Until I finally got her started.

I am hearing a rather loud knock, that I cannot quite pinpoint. I did a search on "603 knock" and "noise" in the diesel forum and I cannot tell exactly what I am hearing (injector, lifter, rod). It seems to idle ok, power is up there (pulls hard at 2500 or so), smoke seems low, and the sound seems to come and go. It almost seems too loud at times to be injector noise but I am not familiar enough with these cars to know. I listened to the clips that people posted last year and mine definatly sounds worse than those. I am trying to make a recording this weekend. If I am successful, I would love your opinion on the matter?

other pertenant factors:

- not currently using Synthetic oil (will switch soon)
- I have tried my somewhat local (live in the sticks of CT) german parts jobber for Diesel Purge and he cannot get it (or won't)
- I have looked for a place to get injectors tested and haven't had much luck.

I know this subject has been beaten to death but I am feeling a little discouraged and could use some assistance.

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Dean

Is it possible that one of your hydraulic lifters is lazy? When you say that it seems to come and go, it may take longer for oil pressure to fill that lifter but as soon as you drop to idle the lifter starts tapping again until you repeat the above. This is one possible scenario, but you need to define if it is a "tap" or "knock" Also, a lifter will have an even amount of time between taps such as tap---tap---tap---tap--- but if it is tap--- tap- tap---- tap-- it is more likely a nailing injector.

A rod will knock at idle with no torque load, when there is a torque load say upon acceleration, the knock will disappear, but after you reach a constant speed such as 20 or 30 mph, the torque load has lessend and you may begin to hear the knock sound again depending on just how worn the rod bearing is. A really worn rod bearing will sound knocks even under greater torque loads and at some point just before the rod goes through your block, the knock is present at any torque load, and louder!

Wrist pins are similar but with a different personality!

Like the hydraulic lifter, a rod knock has an even amount of time between knocks and were talking fractions of a second here! It can be difficult to an untrained ear to detect these sounds so it was a good idea to attach sound to your next post.

Looking forward to hear your download.

Have a sunny day..

Well here it is. This recording is of the first start of the morning in sub freezing northern CT weather. I will drive it some and get a better recording of it warm. There is a lot of clatter to be able to pick out the knock but you can hear it near the end of the clip. here is the link to my home page and the clip is "noisy 603"

I actually had to combine all of the clips (5) into one and resize them to fit on the web page. the first portion is of the cold start and the remainder are of the warmed up run. I will attempt a better sample but this is a start.

http://webpages.charter.net/deanot442/

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Dean

Why we have almost identicle cars but with only one difference, my interior is light tan, while your's is dark tan! Milage is almost the same too!

I listened to your download of your engine and can hear bad hydraulic lifters and very loud I might add! At 232K, your engine is in need for new lifters. With new lifters, you would be amazed how much quieter and smoother and with more power too!

I also heard an occasional clicking sound asside from the lifters in the first sound bite and I have heard that same sound before in my engine too! After I had installed rebuilt injectors more than a year ago, that sound never returned.

In the last sound bite, sound from inside the car, it seemed like a thumping sound, but that may just be audio bouncing around.

It will be interesting to read more opinions on your sound bite to see what others come up with?! BB

Deanot442, how long have you owned your 87 300D? Have you ever had any trouble with your tranny?

BB

I have had this car for about a year, and my wife's wagon for around the same. My wife’s shifts very smooth (especially after I changed the fluid and filter), and mine shifts a bit harder, but both are ok as far as I can tell.

There are several other posts concerning trannies for these cars on this forum as well as on yahoo’s Mercedes diesel forums.

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Dean

Wow I would say really bad lifter! I don't think it is an injector but try losening one line at a time and see if it goes away.

All 603's seem to get bad lifters synthetic helps a lot but the only 100% solution is to change them then use synthetic.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Sounds like a lifter. Do you have a good belt tensioner? When mine went bad it sounded rough and blended in with the lifters amplifying the noise.

For injector work, I would recommend H&L Diesel in Deep River. They were fair to me.

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Pete what did you have done there?

Also to all, I just made better recordings of the car tonight. Here them at the same above web page.

These are of much better quality!!
a. is with the hood open and mike near the open hood
b. is under the car
c. is in the car with the windows shut
d. was recorded while driving ( kind of windy but... you can really hear me passing the trees). the last half of d. is back in the garage with the windows open.

I feel this is a combination of several issues.

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Dean

Dean, I did not hear anything new on your latest sound bites. I still say your lifters are very loud and would say too that injectors do nail but not real bad!

Replacing hydraulic lifters is pretty easy to do. Basically you need to remove the cam and then with your fingers pull each one out. The only trick is to have a diagram of the cam removal sequence. (I can fax or download this info for you) You have to have the cam positioned at the right place, and unscrew certain bolts in sequence. It's real easy to do. New lifters the last I heard were around $27 each, but price around, you may find them cheaper.

I have had the same problem and it also was he belt tensioner. Actually I am due for another replacement as on cold mornings I have a rock tumbler under the hood I have 240,000 on my diesel.

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91 350 SDL
91 300 E
85 300 D (sold)
79 300 CD (sold)
91 300 CE

The Bosch shop in New Haven I use will test the injectors for $10 each, and they offer rebuilds for around $90 each. They also warrenty them and stand behind their work. I would recommend going that way, sure you can order them online for $55 each but 1/2 will be bad out of the box. I made the mistake of ordering 6 online in hind site $90 each is a bargin.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200