What did the mechanic do?!?! - PeachParts Mercedes-Benz Forum

Hirnbeiss · #1 10-19-2008, 08:35 PM

The "loose valve" diagnosis is bogus. The tapping is most likely tappet noise caused by excessive clearance. One or more of your hydraulic lifters are stuck, preventing automatic clearance adjustment. They can sometimes be whacked with a mallet to free up or by cleaning with something like Rislone, otherwise it's lifter replacement time.
At 116K, this engine should have plenty more life left in it, but you will need to maintain it regularly. I fgure a car always costs at least $200/month: either in average maintenance expense, or in regular car payments. You will also have extra to catch up on the "defrred maintenance" (aka neglect) of the prior ownwer.

Jed89300E · #2 10-19-2008, 08:51 PM

...for helping me out. Another friend told me it was probably a lifter, but with hearing about the supposed "tightening of the valve", I was a little more concerned, since I am not a mechanic - it sounded more sinister than a lifter. I apologize for the 'rookie'-type question I asked, but appreciate your helpful answers. I'll be more careful next time and promise to pass on anymore $100 deals to you guys.
Jed

mpolli · #3 10-19-2008, 09:21 PM

[QUOTE=Hirnbeiss;1997194]I fgure a car always costs at least $200K/month: either in average maintenance expense, or in regular car payments.QUOTE]

You and Paris Hilton are the only 2 people spending this much on cars!

Hirnbeiss · #4 10-20-2008, 07:15 AM

[QUOTE=mpolli;1997232]

Quote:

Originally Posted by Hirnbeiss

I fgure a car always costs at least $200K/month: either in average maintenance expense, or in regular car payments.QUOTE]

You and Paris Hilton are the only 2 people spending this much on cars!

OK, OK it's budget season - I have too many K's on the brain!

I'll edit out.

david s poole · #5 10-20-2008, 10:44 AM

based on your info,i would think that your problem lies with the bolts that hold down the rocker assemblies.the head is aluminum and the bolts are steel and one or more of the bolts [probably on one assembly] have pulled loose.there are two choices.find the bolt[s] with the pulled threads and buy some bolts that are 10mm longer [at the threads]and you can take advantage of the extra unused threads at the bottom of the hole.tighten to about 15ft/lbs.or to do the job correctly,buy a helicoil kit and redo the damaged holes.this is a permanent fix.you can do this job yourself.good luck.

Jed89300E · #6 10-20-2008, 08:52 PM

Quote:

Originally Posted by david s poole

based on your info,i would think that your problem lies with the bolts that hold down the rocker assemblies.the head is aluminum and the bolts are steel and one or more of the bolts [probably on one assembly] have pulled loose.there are two choices.find the bolt[s] with the pulled threads and buy some bolts that are 10mm longer [at the threads]and you can take advantage of the extra unused threads at the bottom of the hole.tighten to about 15ft/lbs.or to do the job correctly,buy a helicoil kit and redo the damaged holes.this is a permanent fix.you can do this job yourself.good luck.

That makes sense. I feel confident doing this myself. Thanks a ton!

Johnhef · #7 10-20-2008, 10:54 PM

Quote:

Originally Posted by david s poole

based on your info,i would think that your problem lies with the bolts that hold down the rocker assemblies.the head is aluminum and the bolts are steel and one or more of the bolts [probably on one assembly] have pulled loose.there are two choices.find the bolt[s] with the pulled threads and buy some bolts that are 10mm longer [at the threads]and you can take advantage of the extra unused threads at the bottom of the hole.tighten to about 15ft/lbs.or to do the job correctly,buy a helicoil kit and redo the damaged holes.this is a permanent fix.you can do this job yourself.good luck.

I was reading through the replies to your problem and came across this one, this is exactly what I was going to suggest... so I second it

Jed89300E · #8 10-21-2008, 08:24 PM

Quote:

Originally Posted by Johnhef

I was reading through the replies to your problem and came across this one, this is exactly what I was going to suggest... so I second it

Thanks for that. This one makes the most sense, since there was some "tightening" of some "bolts" somewhere along the line. I have a pal with a helicoil kit and plenty of MB knowledge. We're going to get into it next week. I'll post an update and some pictures if anyone is interested. Thanks again to all for helping a newbie out.
Jed

hanno · #9 10-21-2008, 09:03 PM

Agree with the rocker assy bolt(s) at this stage, but believe that the cam/lifter was the cause of the initial ticking. "tightening" by a non-MB familiar tech will result in the bolt holes being stripped. I think the required torque is less than 15 lb.ft. I had to do 3/4 of them in a replacement head from an outfit that had "international" in their name. The international didn't include German

It had about 6 that wouldn't hold on the bench test, another group that just looked bad, and group "c" that didn't hold at final install. The kicker was the instructions that actually stated that a "heli-coil was something that anyone can do". I didn't argue with that, I just didn't take if for a huge hint.

waybomb · #10 10-21-2008, 10:03 PM

Quote:

Originally Posted by Jed89300E

Thanks for that. This one makes the most sense, since there was some "tightening" of some "bolts" somewhere along the line. I have a pal with a helicoil kit and plenty of MB knowledge. We're going to get into it next week. I'll post an update and some pictures if anyone is interested. Thanks again to all for helping a newbie out.
Jed

Do youreslf a favor. If there is room, use a Keensert instead of that helicoil spring.