valve job? - Page 9 - PeachParts Mercedes-Benz Forum

leathermang · #**121** 03-16-2018, 07:43 AM

Quote:

Originally Posted by vwnate1

Be smart and pay him to check it out correctly ~ you may well find it has tight valves and a worn our drooling fuel injector, these little things make an amazing difference when corrected ..... .

Or if you have one of the INDEPENDENT services available.. ( Lemon Busters types ) which will do a lot of tests and give you the results... I think typically for just over $100 .. at least since they have no dog in the fight.... they do not do any repairs... that nagging suspicion that a mechanic is ( perhaps unconsciously ) biased towards some fixes which add to the labor cost....

Might be an advantage....

vwnate1 · #**122** 03-16-2018, 08:51 AM

That'd be good *if* they have the proper tools to test both mechanical fuel injetors on 30 + year old engines (you know they don't) and also the proper Diesel engine compression tester, again you already know they don't so the O.P. here is kinda stuck .

Clearly he's already spent money on 'mechanics' who are in competent to work on old Diesel engines at beast, flat dishonest at worst .

NO ONE checks four out of five cylinders if they have any idea what they're doing or are honest .

As a Journeyman Mechanic I get pissed off quickly when I see this sort of crap .

leathermang · #**123** 03-16-2018, 10:14 AM

Quote:

Originally Posted by vwnate1

That'd be good *if* they have the proper tools to test both mechanical fuel injetors on 30 + year old engines (you know they don't) and also the proper Diesel engine compression tester, again you already know they don't so the O.P. here is kinda stuck .

Clearly he's already spent money on 'mechanics' who are in competent to work on old Diesel engines at beast, flat dishonest at worst .

NO ONE checks four out of five cylinders if they have any idea what they're doing or are honest ......

While I agree that standard full inspection would not likely include the mechanical fuel injectors...
I do not think they could be in business without being able to test the compression on Diesels... as that is the primary indicator of the engine condition...
He could ask them.....and watch while they do the test.. most of them will meet you at a parking lot or someplace of your choice...

allenying · #**124** 03-16-2018, 09:25 PM

as i'm thinking about it, maybe i should ask rheinland if they will skip his diagnostic and do the valve job on #1 cylinder. idk if he will, but it might be a good test to see if he just wants work, or not, cause i could easily not be a future customer if i ditch this car. i'm not sure that he cares cause he has other customers, but who knows, who doesn't want new customers/

these are the reasons it was narrowed down to cylinder #1:

on 1st valve adjustment, 1st exhaust valve, lock nuts were loose, valve was extremely tight, no gauge could fit. the rest all needed adjusting.
compression test was done, 1st cylinder had lower compression, than the next 3, the 5th wasn't tested due to time/light constraints, and the 5th valves needed the least adjusting.
the problem was actually fixed, but only temporarily, injector nailing started, then the rough running and smoking again. then a new bosch injector was installed on 1st cylinder, no change.

5-6 wks and 850 miles later, 2nd valve adjustment, 1st exhaust valve again was so tight that not gauges fit. the rest were all pretty close to spec, either left of slightly adjusted.

12 days and 200 miles later, 3rd valve adjustment, 1st valve was a little tight, 0.013", the rest were at spec. leak down test was done on 1st cylinder, a leak was heard w/ microphone and headphones at exhaust, it was hard to hear w/o headphones above ambient noise, wind, trees, highway nearby. 1st injector, the new one, was swapped w/ 2nd injector, the nailing stayed in the 1st injector, confirmed by cracking it open 1/4 turn to hear when it go away. they were also pop tested and spray pattern checked in the process.

who wouldn't put their money on the 1st valves after that?
again i'm not an expert, but still... curious...

i'm not sure if timing chain has every been changed, it looked good, but what can you tell from looking.

but other reasons to think it's not something else, cold starts were good most of the winter, down to mid 20s or so. but, if i didn't give it throttle on temperatures below freezing, it would stall out, until engine full temp. that i thought was also due to low compression, lower temperature, lower pressure.

do these details change anyone's mind about the $1000 initial diagnostics?
i mean why not do the 1st cylinder valves, first?

leathermang · #**125** 03-16-2018, 11:01 PM

Due to the percentage of the work which is required just to get TO that number one set of valves.... I think he would think you were crazy to be considering having him just do one cylinder...
Read the thread in my signature about checking chain elongation.. you can't tell anything by looking...

allenying · #**126** 03-16-2018, 11:32 PM

yeah i didn't think looking at chain would tell much,

sure, do all the valves, my main point was skipping the diagnostic work that was already done, based on the results.

thanks,

leathermang · #**127** 03-17-2018, 12:04 PM

Yes, even if you need other stuff like the fuel system I think you have determined that you need a valve job.....
Only fix one thing at a time if you want to know later what exactly the problem was....
Fix, Test, Fix more, Test again...
Some people don't believe in that ... but Curious Minds want to know
LOL

vwnate1 · #**128** 03-17-2018, 12:45 PM

Or ;

You could just drive it as is as you've said it runs fine and only has problems when cold started if you don't give it some throttle .

I put close to 80,000 miles in my '82 240D's worn out low compression in #1 cylinder engine before rebuilding it, it shook pretty badky at hot idle because that cylinder had a soft miss due to under 200# compression .

It still got 27 ~ 34 MPG on road trips and didn't burn much oil ......

You seem adverse to putting much $ into this car, it's normal to need to re adjust the valves several times are they've been allowed to run tight .

Unless you don't actually like the car, just drive it and don't give up .

funola · #**129** 03-17-2018, 01:09 PM

Quote:

Originally Posted by vwnate1

That'd be good *if* they have the proper tools to test both mechanical fuel injetors on 30 + year old engines (you know they don't) and also the proper Diesel engine compression tester, again you already know they don't so the O.P. here is kinda stuck .

Clearly he's already spent money on 'mechanics' who are in competent to work on old Diesel engines at beast, flat dishonest at worst .

NO ONE checks four out of five cylinders if they have any idea what they're doing or are honest .

As a Journeyman Mechanic I get pissed off quickly when I see this sort of crap .

You calling me incompetent and dishonest? I have a few words I would call you, but I am not going down that path.

allenying · #**130** 03-17-2018, 05:12 PM

I think VWNate was just basing on what I was saying, which wasn't full details.

anyway, I was saying that the engine started up fine in winter, but it is really not a pleasure to drive with so much smoke and shaking. i've been driving it like that for over 6 months but still it just feels really wrong and like I am damaging the engine more.

I can't say that my fuel mileage has been good, but that is also maybe because of a cold,

I will call on Monday and ask if they will address the valves before addressing the fuel system, and find out how much, thanks

vwnate1 · #**131** 03-17-2018, 07:53 PM

I don't know what I called you .

What I said after 50 + years of being a mechanic was : failure to do the complete job indicated incompetence or laziness .

I see it all the time, fully 90 % of every job I do, involves correcting previous 'repairs' , often clearly done by patently dishonest 'mechanics' and I am pretty angry too as we all who make our livings fixing things, get painted with the broad bush after someone else makes a bad job of things .

I had no intention of maligning you personally, I had no idea who it was who'd given the PO bad advice .

vwnate1 · #**132** 03-17-2018, 08:19 PM

Damn ~ this really strikes me hard .

I take the Job *very* seriously, mind you, I'm of the generation that used to run out portable boring bars that bored *one* cylinder and other (IMO) 1/2arsed patch repairs .

I lost track of the valve jobs that were done on marginal engines and so created either smoke blowing junkers or blew the conneting rod bearings out shortly after .

Yes, I realize our Mercedes OM engines are over engineered so it's often possible to simply slap a fresh cylinder head on an old mystery bottom end but in the big picture this is very unwise unless you've made a detailed inspection first and not testing every cylinder in any engine before suggesting patch work, is IMO (worth nothing I realize) incompetent at best .

The OP here is running in circles and chasing his tail here .

allenying · #**133** 03-17-2018, 09:23 PM

I think the main reason I went in a circle is because of what this shop was saying, otherwise I was ready to just have the valve job done, after hearing what he said, and what everyone here said, I'm back to being ready to have the valve job done. i'm just trying to be careful because I know you guys are very knowledgeable,
thanks,

vwnate1 · #**134** 03-17-2018, 09:24 PM

O.K. then ;

Let us know how it works out .

Maxbumpo · #**135** 03-19-2018, 11:47 AM

Allen,

I see nothing in your write up of diagnostic work about addressing the injection pump by rebuilding the #1 delivery valve. I do agree that there is a compression problem with the #1 cylinder, but I think you may also have a problem with the injection pump at the #1 delivery valve or internal to the injection pump. In your place I would pay either of your shops to remove the #1 delivery valve, inspect, and either replace (if damaged) or rebuild with a fresh copper washer and make sure it is properly torqued for your engine. Another approach would be to replace the entire injection pump with a rebuilt unit, which would accomplish the same thing but cost far more money.

#1 DV is removed when the injection pump timing is checked with the factory method (drip timing) and so it may have been messed up during such a procedure.

This delivery valve work is far less expensive and time consuming than pulling the head for a valve job, and I have fixed a very similar smoking / kicking problem on my '87 300TD.