Timing chain problem - PeachParts Mercedes-Benz Forum

86420 · #1 08-06-2006, 03:18 PM

Need some some help/experienced opinions.....love this forum...first time posting.
Wife parked car at home, 420SEL. No problem as far as she noticed....next day car won't start....will turn over..no start. She tries starting the car in a span of 5-6 minutes...stops.
She calls me....I tell her to call a mobile mechanic...to diagnose the problem. He's fixed a vibration/tierod problem before/ done a tuneup/ looked over the car etc. about a month ago. I've been looking for another mechanic in addition to the one who's done some minor work on the benz because he is pretty busy most of the time.

He checks the engine at the house....wife calls me with diagnosis... no compression at passenger side of head....timing chain problem....most likely valve damage.He will fix t-chain,damaged valves replaced..$4,500..WOW.Has car towed to his place..calls next day..waterpump needs changing..$400 add...$4,900.
2 days later, calls again..more bad news...found a broken piece of the guide railing left side/passenger side.
Bottom line....add $2,000 more for total of $6,900..BIG WOW!!!!
Does anybody feel sorry for me yet

I ask him where are you at as far as teardown....he says valve covers/manifold etc.
I also ask him how much to I owe him at this point...he says well at this time for his labor $2,000.
That is the excact amount he wanted upfront before he left the house...surprise,surprise.
I tell him tow the car back to the house.
Explaining the problem as best as I could above....can this much damage occur to the heads/valves turning the engine over for 5-6 minutes maximum to try to start??????
Remember, wife drove the car home with no problem according to her, parked it and could'nt start it next day.
Mechanic????? showed me the broken piece guide rail but come on now.
The car wasn't running/driving and all this damage????? $6,900....

Any toughts and opinions are greatly apprecciated.THANK YOU!

Tomguy · #2 08-06-2006, 03:45 PM

Well of course the rail broke! The m116 engines that have not had timing chains or guide rails ever replaced are notorious for doing this.

He's taking you for a ride. $4500 for ONE HEAD? Ridiculous. What's the extra $2000 for? BS. Rails aren't more than $50 in parts and no more extra labor if he's taking it apart to do the heads anyway. The bottom rails don't need to be touched until about 500k miles usually. The tops are the ones that get beat. Therefore, you don't need to pull the engine or take the front timing cover off or anything.

Gilly · #3 08-06-2006, 04:20 PM

For those prices you could get in to a very good reman long block from MB or Metric. I don't doubt the diagnosis though, yeah those things start making REAL expensive noises in a hurry. I'm not seeing the mileage on the car listed anywhere......
Gilly

86420 · #4 08-06-2006, 08:04 PM

Quote:

Originally Posted by Gilly

For those prices you could get in to a very good reman long block from MB or Metric. I don't doubt the diagnosis though, yeah those things start making REAL expensive noises in a hurry. I'm not seeing the mileage on the car listed anywhere......
Gilly

Thanks for reply Gilly. Cars mileage....151,830

Gilly · #5 08-06-2006, 08:43 PM

WOW 150K on it, way too soon for something like this to happen ("damn straight" I can hear you say). And wife says no expensive noises? You should at least get the entertainment value of hear things crunch. BIG problem now is this guy saying $2K for removing the intake and valve covers. Don't know how to get around that, not much on that end of things. I think tomguy may be wrong, and he can correct me, but rails mean pulling the timing covers off, big work. I still think the mechanic is way high, but yeah a considerable more amount of work, but expected, usually a busted chain wipes those out pretty quick. But wife should have heard a pretty loud commotion out front. How'd the guy arrive at the fact it needs a waterpump, this damage should have no bearing on the water pump at all, just thought he'd look around for MORE work to do? Have you have to add coolant or in any other way can you verify the pump was going? It's good to want to do SOME extra work, in the case where you'd have the pump removed anyways (such as removing the timing covers) and it seems rough or noisey for example, and an honorable man would just throw it in on the deal (the labor) if it is removed/installed in the course of the work at hand (I know the pump on these V8's are pricey btw, so maybe the $400 IS just for the part). BUT the thing that bothers me about this guy is that if he just has the valve covers and intake manifold off, how does he know at this point the water pump should be replaced? Guy sounds really flaky to me.

Gilly

Strife · #6 08-06-2006, 08:55 PM

Comments:

1. The water pump is easily accessible and done when the rest of the work is being done, darned considerably less than the book 6 hours.

2. The UPPER guides don't need timing cover removal. HOWEVER, if a piece or pieces fell in the engine, I'm pretty sure some serious work is required to drop the oil pan to get it, unless you are lucky and can account for everything. There have been SOME who have left them there - personnally, I wouldn't do this.

3. Even a genuine MB part is less than the price you mention for the water pump, list. Less expensive replacements (some have iffy opinions about them) are available.

4. 150K is "not too soon"; I think # of years are also involved.

5. Typically this DOES happen at startup; the consensus is that the tensioner (which you also MUST replace but not very expensive) gets old, leaks, and doesn't keep the chain tight upon startup until oil pressure returns, the chain slaps the guides, they break, and so forth. BTW check your valve cover to see if it cracked - used, not too bad but $$$ new.

86420 · #7 08-06-2006, 08:02 PM

Quote:

Originally Posted by Tomguy

Well of course the rail broke! The m116 engines that have not had timing chains or guide rails ever replaced are notorious for doing this.

He's taking you for a ride. $4500 for ONE HEAD? Ridiculous. What's the extra $2000 for? BS. Rails aren't more than $50 in parts and no more extra labor if he's taking it apart to do the heads anyway. The bottom rails don't need to be touched until about 500k miles usually. The tops are the ones that get beat. Therefore, you don't need to pull the engine or take the front timing cover off or anything.

Thanks Tomguy for your response.Cars mileage....151,830