I have heard that some mbz's use plastic timing chain guides!? Is this true?
Does the 1988 190e 2.3 and 1989 560sel use plastic timing chain guides? My mechanic said that is does not matter if you change the chain if you dont change the guides, the plastic will allow the new chain the "slap" and it will be out very soon. All input appreciated here..

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1996 E320
2000 C230 Kompressor
1988 190e 2.3 - 225K miles, owned for 7 years. I cannot say enough good things about this car. Very well built, even at 225 it ran like new.

I don't know about the 190, but the 560 definitely has plastic
guides. I replaced mine at about 112K and they were in need of
replacement. They were very brittle and a deep brown color.
Find out if the 2.3 has plastic guides. The popular sentiment
is to change them at 100K or 10 years. Don't wait. The cheap
plastic can fail and destroy your engine. A used 560 V-8 runs about
$2700.

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VR
1967 250SL

I was wondering how many hours your shop charged you to change the guides? My Bosch certified mechanic wants to roll on a new chain and replace the tensioner. I expect, in his view, the guides are not at issue here. Do you know if the guides can be replaced without taking off the whole front cover of the engine? 91 560 SEL 97K miles.

thanks
Jim

In my case, the chain was perfectly tight and I haven't had
any problems with the tensioner. I think I saw that the
tensioner will allow the chain to rattle especially as the
oil pressure builds up. Anyway, Landi took off the valve
covers and replaced the top rails. This was a total bill
of $250, but he did do a little more work on a broken stud.
Landi charges $60/hour. As he explained, it is the top rails
that shatter and fly into the cam gear. The lower guide is
not as big a risk, (statistically). I agreed so we had the
top guides done only. The lower guide would involve the whole
front engine components being removed and several more hours.
I am going to replace the entire chain, lower rails, tensioner
when it gets to 200K or if the water pump fails.

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VR
1967 250SL

I recently had the timing chain, tensioner and top rail on my '88 420SEL replaced for $360 labor. I supplied the OEM chain, tensioner, rails and valve gaskets which I got myself for $165 total and the independent agreed to use. I had 77,000 miles, but had recently bought the car from an older couple and it had not been driven much in the last several years (i.e., the low mileage).

There was a little bit of play in the chain, so they went ahead and replaced it (I was also having the smog pump replaced and asked them to check the chain) and the top rail. They said that the top rail showed a little wear but that the bottom guides were fine, so they did not replace them (I had supplied the bottom guides as well -- a total part cost of $6).

I was a little annoyed that they did not do all the guides since I had gone to the trouble of getting them, but they assured me I had nothing to worry about since the top is the trouble-maker (and based on your post, saved me a couple of hundred in labor costs). These folks come well recommended and seem knowledgeable, so I will go with their recommendation and, like you, just do the bottom at a later cycle or when something in the way has to be dealt with anyway.