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Chain tensioner..

7K views 27 replies 13 participants last post by  Geach 
#1 ·
#2 ·
#4 ·
I'd always considered the e36 tensioner a sensible upgrade.

However, reading a recent Total BMW article where Andy Everett did a feature on Stannard Motors, Les Stannard said that the e36 tensioner puts excessive wear on the guides and wears them quicker. He was talking about the S14 but I can see the same being relevant to the S38.

I'm now unsure what to do with mine as I respect what Les Stannard has to say. I ran one of his 2.7 M20 engines in my e30 - it's now on about 100,000 miles in the hand of its current owner and hasn't been off the limiter its whole life.

I'd planned to swap to the e36 tensioner. I may well fit a standard tensioner along with new guides, check the sprockets for wear and replace them if needed.

Another thing worth checking is end-float on the crank. This has been known to be a cause of chain skipping problems and usually goes overlooked.
 
#5 ·
bay said:
Swap ?

If I understand you correct this is not a good thing to do ?

bay
swap = exchange
 
#8 ·
bay said:
Have one of you guys try to install the chain tensioner from a M3 S50B32 with part number 11 31 1 405 081 ?

http://www.bmwe34m5.com/faqs/?theme=1&level=4&question_id_select=438&chapitre_id_select=37&document_id_select=3

Bay
I've done this swap on several S14s, M88s, and S38s, and have NEVER had a problem. It is a squeeze to get your hand down there, especialy if the car has AC, but it is very worthwile!

I read the story about extra strain on the guides, and regard it as BS for the following reason: I doubt the total pressure on the chain is higher then with the old tensioner at max-oilpressure. The only difference is that the chain is kept at that pressure continuously, giving a nice steady chain that doesn't flop around or vibrate against the guides.

If the original tensioner is working properly (read: bled regularly) it would probably keep the chain on decent tension, but since most have lots of air in them and start with NIL pressure, the chain is eating up the guides a lot quicker than a properly tensioned chain would. And a worn guide will fail no matter what, tension or not. Tension just keeps wear down, ask any enginebuilder.
 
#10 ·
Cam chain tensioner S38B36

I have just carried out this mod on my car and whilst I cannot say whether to use the E36 part or standard I would recommend any M5 owner replace the tensioner when first acquiring a car.
My engine was quiet on startup hot or cold but had an annoying noise at 2000RPM which only manifested itself when the engine was at normal operating temperature. It sounded like a heat shield or CAT resonance and as it seemed to be temperature related and RPM rather than load dependant I settled for that explanation.
It was only when checking the installation of a new water pump that I listened to the engine properly with the bonnet open and realised that the noise was coming from the front end of the engine and was 10 times worse than I'd realised!
The noise was similar to a Jaguar V12 I owned years ago which was diagnosed with cam chain and tensioner wear although in that instance the noise was at about 1000 RPM. I ordered a new tensioner (E36 M3 EVO type) and fitted it as soon as it arrived from the dealer. The instructions on this site from Raymond Woertman were invaluable throughout. I took the precaution of removing the cam cover whilst carrying out this work to inspect the chain and sprockets which seemed to be fine. I also checked the valve clearences and the spark plugs whilst everything was apart.
To my releif the engine now displays no sign of this noise and I consider the replacement of the tensioner to have been 100% successful. The bore and piston of the original tensioner (diaphram type) were badly scored and worn so no doubt the essential oil pressure was being lost causing the cam chain to rattle noisily, the situation at it's worst when the oil was hot and therefore lower in viscocity. I feel certain that if left to develop this situation would have led to the valves having an untimely meeting with the pistons and my otherwise excellent M5 ending up as spare parts!
My message is don't mess about, if there is any doubt whatsoever as to the condition of the tensioner get it changed, for around £60 and an hour or so labour you could be saving your car from the indignity of an early journey to the breakers.
As to the debate surrounding original vs E36 EVO tensioners who knows?
It is possible that the pressure exerted by the newer tensioner is greater but it would be difficult to determine by how much and if this was in fact detrimental to the other components in the system. Perhaps a forum member with a good working knowledge of hydraulics could calculate this?

P.S Apologies for the legth of this post!
 
#12 · (Edited)
It's not that there is increased pressure in the E36 one, it's just that there is constant pressure from the start created by the spring, rather than having to wait for the oil to come up to pressure.
 
#15 ·
shuggy47 said:
I figured they knew what they were doing when designing it so why second guess them.
It's a design flaw in the S38, which BMW ignored until the lack of oil-pressure and coinherant incorrect timing started throwing fault codes in the dual-VANOS system of the S52. Only then did they step up to the mark and design us a proper tensioner......

Replacing the old one by an old version is playing russian roulette, and as far as I know the old part was phased out for the new one.......
 
#16 ·
andy36 said:
I have just carried out this mod on my car and whilst I cannot say whether to use the E36 part or standard I would recommend any M5 owner replace the tensioner when first acquiring a car.
My engine was quiet on startup hot or cold but had an annoying noise at 2000RPM which only manifested itself when the engine was at normal operating temperature. It sounded like a heat shield or CAT resonance and as it seemed to be temperature related and RPM rather than load dependant I settled for that explanation.
It was only when checking the installation of a new water pump that I listened to the engine properly with the bonnet open and realised that the noise was coming from the front end of the engine and was 10 times worse than I'd realised!
The noise was similar to a Jaguar V12 I owned years ago which was diagnosed with cam chain and tensioner wear although in that instance the noise was at about 1000 RPM. I ordered a new tensioner (E36 M3 EVO type) and fitted it as soon as it arrived from the dealer. The instructions on this site from Raymond Woertman were invaluable throughout. I took the precaution of removing the cam cover whilst carrying out this work to inspect the chain and sprockets which seemed to be fine. I also checked the valve clearences and the spark plugs whilst everything was apart.
To my releif the engine now displays no sign of this noise and I consider the replacement of the tensioner to have been 100% successful. The bore and piston of the original tensioner (diaphram type) were badly scored and worn so no doubt the essential oil pressure was being lost causing the cam chain to rattle noisily, the situation at it's worst when the oil was hot and therefore lower in viscocity. I feel certain that if left to develop this situation would have led to the valves having an untimely meeting with the pistons and my otherwise excellent M5 ending up as spare parts!
My message is don't mess about, if there is any doubt whatsoever as to the condition of the tensioner get it changed, for around £60 and an hour or so labour you could be saving your car from the indignity of an early journey to the breakers.
As to the debate surrounding original vs E36 EVO tensioners who knows?
It is possible that the pressure exerted by the newer tensioner is greater but it would be difficult to determine by how much and if this was in fact detrimental to the other components in the system. Perhaps a forum member with a good working knowledge of hydraulics could calculate this?

P.S Apologies for the legth of this post!
My car has a definite noise around 2000 rpm that sounds like something rattling...almost a surging kind of sound, I was wondering if it was the throttle bodies needing synchronising as they are only barely cracked open here. There is no noise at startup and the noise is there from 1750 to 2250 rpm at all times whether hot or cold.

Anyway, with the FAQ site seemingly being not fully restored yet, are there any other guidelines on how to replace the tensioner. I'd like to do it myself.

Thanks
Richard
 
#17 ·
milesr3 said:
My car has a definite noise around 2000 rpm that sounds like something rattling...almost a surging kind of sound
Sorry to reply to my own post, but other might find this useful.

I changed the timing chain tensioner today and put in the M3 Evo part.

It was actually a lot easier than I was expecting. Had it done in an hour including removing the washer bottles and taking about 10 attempts to convince myself that the piston was in the right place. Filling the sleeve with oil helped.

My original tensioner didn't seem too bad. There was a little scoring on the piston, but the spring felt like it had plenty of tension in it.

Wow - what a difference. My chain didn't rattle at idle at all, but there was a really noticeable rattle from 1750 to 2250 and a surging feeling, which I assume was the cam timing wanging about all over the place. The engine is much quieter and smoother now throughout the whole range, so the old one was probably pretty bad after all. Definately a good hour's work.

Richard
 
#24 ·
Engine is running sweet, going to replace the chain tensioner and get the valve clearences done.
Must have done roughly 3000miles since the re-build, had a few issues along the way but everything is looking good now.
Im currently writing a report on my rebuild and will post as soon as it is finished.
Cheers for the interest bay.
How's your beast getting on?
 
#25 ·
Hi

I sold the engine :crying2: but there was a guy who paid 9300 euros for it okay price. So next week I drive to germany to get a 3,8l from 1995.
I will send some pics when I get it...

Bay :cheers:
 
#26 · (Edited)
bay said:
Hi

I sold the engine :crying2: but there was a guy who paid 9300 euros for it okay price.
Mr Daniel Geach are you reading this? Mathematically if a 3.8 brings €9300 a 3.6 should get you € 8810.5 *





* joking, I'm not THAT stupid actually!
 
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