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Discussion Starter #1
I sometimes get a "phwap phwap phwap" noise at start up. Very rarely. It definitely isn't a "jingle" and it goes away when oil pressure comes up.

I believe this is a symptom of a tired chain tensioner.

I'm really not in the mood right now for a complete chain, guide, etc replacement. However, looking at the tensioner it looks like it is held in by 3 allen bolts. I know the chain, guides, and everything else were done back in 2006 or 15k miles ago. Yes I know, age is worse than miles.

In the interim, i'd like to buy more time before joining the chain gang.

Is my understanding of R&Ring this part as easy as:

1. Remove 3 bolts
2. Pull out tensioner and gasket
3. Put new gasket and tensioner in
4. Torque down

Mission accomplished.


I find it hard to believe it is that easy. Am I missing something?
 

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I think I read somewhere that its difficult to reattach the Chain Tensioner using the same bolts. If I recall correctly, you need to find a longer bolt to temporarily get it tight enough to the block for the other bolts to go in.
Not 100% sure though. Maybe someone else will chime in.
 

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Discussion Starter #3
I think I read somewhere that its difficult to reattach the Chain Tensioner using the same bolts. If I recall correctly, you need to find a longer bolt to temporarily get it tight enough to the block for the other bolts to go in.
Not 100% sure though. Maybe someone else will chime in.
No you're right, I just found that thread:

https://www.benzworld.org/forums/r-c107-sl-slc-class/2044353-chain-tensioner-replacement-quick-question.html#post9096729

Makes sense. I can pick those two little M8 bolts up mighty quick.
 

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Beast... you have an '84 380sl, I have an '83. My tensioner doesn't have 3 bolts it has 2 and they are not Allen's they're regular bolts and no, I didn't need to use longer bolts first... the original bolts went right in. 10 minute job at worst.
 

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Beast... you have an '84 380sl, I have an '83. My tensioner doesn't have 3 bolts it has 2 and they are not Allen's they're regular bolts and no, I didn't need to use longer bolts first... the original bolts went right in. 10 minute job at worst.
Hmmm. Aftermarket or OEM tensioner? All the alloy block 107 V/8s used the same tensioner.
 

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I've seen 3 bolt tensioners but mine definitely has only 2.
Yes. Yours is an alloy block. Maybe I should have said all alloy block 107s use the same two bolt tensioner. The three bolt ones are for the iron blocks with AIR pump connection.
 

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Its normal for a chain tensioner to loose tension overnight. Its not normal to hear a rapping noise at start up. The rapping noise at start up after 24 hr rest is caused by worn chain tension guide, worn chain or worn sprockets. You can replace the tensioner if it makes you feel good. But I don't recall replacing one in my lifetime.
 

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Discussion Starter #11
It doesn't happen often at all. When the oil is fresh , the noise doesn't occur at all during start up. Somewhere around the 2k oil change mark is when it starts happening. When I posted this thread, it came back after a long hiatus. Still quite though since then. I plan on changing the oil at 3k.

But I shamefully can't swing a few grand right now. That damn soft top cleaned me out.

Could this just be noisy hydraulic lifters that want oil? I've been considering switching to 0w40 which is rated for the heat differentials we need.

I just need it to go for a few more months to replenish the piggy.
 

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It doesn't happen often at all. When the oil is fresh , the noise doesn't occur at all during start up. Somewhere around the 2k oil change mark is when it starts happening. When I posted this thread, it came back after a long hiatus. Still quite though since then. I plan on changing the oil at 3k.

But I shamefully can't swing a few grand right now. That damn soft top cleaned me out.

Could this just be noisy hydraulic lifters that want oil? I've been considering switching to 0w40 which is rated for the heat differentials we need.
I don't think it would be good to put 0w40 oil in a 35 year old engine. It's summer, you can go much heavier.
 

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Discussion Starter #16
You know, i've resisted buying ZDDP for a very long time figuring my 15w40 diesel oil (first rotella and now Mobil) would suffice.

I'll give it a shot and see if it quiets down. I'm due for an oil change in like 1500 miles I think.
 

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Discussion Starter #17
Update post for all of you.

I was noticing an odd "tap tap tap" noise when accelerating.

I decided to check my oil level and was surprised to see that it was below the bottom one.

I was absolutely terrified! I immediately purchased some ZDDP (x2) oil treatments and added it in along with some extra 15w40.

The noise has subsided considerably. I believe my phawp phawp phawp noise were thirsty hydraulic compensators.

I am blown away because I have only 2500 miles between my oil change and now. I have no obvious leaks or blue smoke out of the tailpipe.

I will monitor oil levels during every fill up from now on. Averted a disaster for sure.
 

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Update post for all of you.

I was noticing an odd "tap tap tap" noise when accelerating.

I decided to check my oil level and was surprised to see that it was below the bottom one.

I was absolutely terrified! I immediately purchased some ZDDP (x2) oil treatments and added it in along with some extra 15w40.

The noise has subsided considerably. I believe my phawp phawp phawp noise were thirsty hydraulic compensators.

I am blown away because I have only 2500 miles between my oil change and now. I have no obvious leaks or blue smoke out of the tailpipe.

I will monitor oil levels during every fill up from now on. Averted a disaster for sure.
I'd be real surprised if "thirsty" hydraulic compensators were causing your noise. I've come to learn that they just don't work that way. Each compensator has it's own oil supply and oil pressure is what replenishes whatever tiny amount of oil manages to ooze out of the compensator (they aren't sealed).

If you had oil pressure (on the OP gauge) then the compensators were getting way more oil than they actually need.
The oil pan holds over 9 quarts, even if the dip stick shows barely to the bottom reading there's still 6 or 7 quarts in there... more than enough to keep the engine lubricated (unless your racing).

How much oil did it take to bring the level to full?
 

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Discussion Starter #19
I have absolutely no idea. I put in 2 ZDDP treatments in and then what I think was a quart of oil.

Perhaps 2 quarts?

The sound has been reduced significantly. There's a small amount of ticking on the passenger side bank, but not nearly as much.

Either way, it sounds like I will be doing a full top end job in the not so distant future. I might just yank the valve cover off soon to see what damage there is.

Figures this shit happens right after I get a new soft top.

Gotta love my money pit of a 380sl!
 

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I have absolutely no idea. I put in 2 ZDDP treatments in and then what I think was a quart of oil.

Perhaps 2 quarts?

The sound has been reduced significantly. There's a small amount of ticking on the passenger side bank, but not nearly as much.

Either way, it sounds like I will be doing a full top end job in the not so distant future. I might just yank the valve cover off soon to see what damage there is.

Figures this shit happens right after I get a new soft top.

Gotta love my money pit of a 380sl!
It's a 35 year old car... I'd say these beauties hold up pretty well for 40 year old technology operating for 35 years.

I'll be pulling the heads this fall... maybe we could coordinate our efforts so we run into similar problems at the same time on opposite sides of the country. :laugh
 
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