S38/M88 reliability

[L_N_Love]

Continuing the thread from the Dinan S38 thread.

My S38 with 48K miles runs so nicely 23 years after it was built. Should I worry that it is going to explode?

[Karl Grau]

Should I worry that it is going to explode?

Yes!
Whatever you do, DON"T drive it. Don't even touch it. In fact, don't even look at it.
If you follow my advice it will provide you with years of trouble free enjoyment.

[mooseheadm5]

Just like any motor, they have their weak points. The M88 timing chain is known to be weak and the heads are more prone to cracking. The S38 does not seem to have these issues. The timing chain and guide rails on the S38 far outlast those on the M88. The it is good practice to replace the timing components around 150k or so, but it is not a strict requirement or anything.

[rcbmw]

The S38-B35 absolutely have issues with the guide rail. The notion that this is not a common failure is wrong and owners must inspect the appropriate timing parts periodically.

Best,
RCBMW

[Dexter]

Should I worry that it is going to explode?

[mooseheadm5]

The S38-B35 absolutely have issues with the guide rail. The notion that this is not a common failure is wrong and owners must inspect the appropriate timing parts periodically.

Best,
RCBMW

I would say that provided the tensioner itself is in good repair that the chain and rails will wear at a normal rate and should be replaced as part of a major service at the appropriate time. Engines that have extended oil service intervals or have suffered other abuse should have the chain, rails, and tensioner replaced earlier.

[Jeremy]

I think the key here, as RCBMW states, is that you should at least LOOK at the timing components to check for excessive wear periodically. You should see the components wearing before something skips a tooth and things go kablooie.

Jeremy

[mooseheadm5]

I think the key here, as RCBMW states, is that you should at least LOOK at the timing components to check for excessive wear periodically. You should see the components wearing before something skips a tooth and things go kablooie.

Jeremy

This is definitely a good plan.

[Mike W.]

Were the E34 3.6 variants better, worse or the same?

[ElGuappo]

Ahh the hot button of the S38 world.

Its not the guides/rails fault inherently, they are made of the same material as the normal M30 guides/rails, and we don't worry about those turning to kibble every 100k miles.

They fragment because of chain slap from a crap tensioner design.

There is a reason BMW changed it in all the later //M engines.

Think about it, BMW doesn't fix something if it ain't broken.

[derrith]

Ahh the hot button of the S38 world.

Its not the guides/rails fault inherently, they are made of the same material as the normal M30 guides/rails, and we don't worry about those turning to kibble every 100k miles.

They fragment because of chain slap from a crap tensioner design.

There is a reason BMW changed it in all the later //M engines.

Think about it, BMW doesn't fix something if it ain't broken.

That's why when you order new s54 vanos bolts they're a different design than the ones I've been taking out.

Mike,

Bmw constantly changed the tensioner design for the m88 and then s38 variants, as well as when the same style continued in the m5x/s5x motors. If the original design had been ideal, that would have not been the case.

[Jeremy]

Is changing the tensioner a fairly simply task compared to replacing all the timing components?

[mooseheadm5]

Minutes vs. hours.

[Mike W.]

OK, so I get the later ones are better, but how much better, a little or a lot?

I also ran across a guy who claimed to have almost 300K on an E30 M3 and said he could tell when things were getting loose in the timing chain department and could go easy on it until he got a chance to change them out. BS or a fine ear?

[mooseheadm5]

If you listen, you can definitely hear a noisy timing chain on startup. You hear that and you need to get in there and do work.

[derrith]

OK, so I get the later ones are better, but how much better, a little or a lot?

I also ran across a guy who claimed to have almost 300K on an E30 M3 and said he could tell when things were getting loose in the timing chain department and could go easy on it until he got a chance to change them out. BS or a fine ear?

The issue with the original design tensioner is that it's slow to tension appropriately on startup, leading to the chain hitting the guide rails, wearing them prematurely.

[mooseheadm5]

This is a good point. Upon thinking about it, I believe that I should either retract or amend my earlier statement. The failure doesn't always track mileage. Some of the noisy low mileage examples had many more cold starts on them than the high mileage examples. A 250k mi car may have far fewer cold starts under its belt than a 45k mi car.

[bac914]

how do you tell the difference between chain slap and valve noise?

And if the tensioner was recently done, and the valves recently adjusted, should there be any clicky noises? I understand the s38 is noisy, but I don't have a point of reference for "normal" vs "need to get in there and do work".

[L_N_Love]

So the tensioner is really the problem. Aren't even the new guides old plastic?


Tell me about other S38s that you know have died from this condition....waiting patiently.

[derrith]

Scottie Sharpe's motor is a relatively well known local example and an anomaly from a mileage perspective for s38s. Rich's is an M88 example.

[Kenny Blankenship]

Continuing the thread from the Dinan S38 thread.

My S38 with 48K miles runs so nicely 23 years after it was built. Should I worry that it is going to explode?

To me, as long as you properly warm up the car before you drive it, don't lug the engine, don't do a lot of stop and go driving and do your maintenence (including valve adjustments) it should be just about as reliable as an M30.

[m-racer]

I have had 2 M88's (1 euro M5, 1 M635CSi). I had both converted to a duplex chain and the guides replaced at 100k. Both were showing wear but not ready to fail. I also replaced the rod bearings and oil pump proactively (I do this with M30's as well and did so on the B9 and on the 535is's). I also had the injectors blueprinted as the heads on the M88's do not like carbon build up. Also a good idea to give the valve train the once over. I replaced the valve springs on the Euro M5, but not on the E24. On the four S38's I have owned, two had relatively low mileage when I sold them. I followed the same protocol at 125k on the last one and the first one went to 209k without being refreshed (was an 88 M5 I bought new and really didn't know better at the time). The guy I sold it to had it rebuilt at 221k. I just think it makes good sense to refresh any motor every 100-125k, as I consider that to be normal maintenance. I hold reliability to be sacred as I drive these cars, so that is part of my thinking as well. Just my opinion.

[rlomba8204]

I just think it makes good sense to refresh any motor every 100-125k, as I consider that to be normal maintenance. I hold reliability to be sacred as I drive these cars, so that is part of my thinking as well. Just my opinion.

It's funny reading the above -- this is what my father tells me about any car pretty much, and why he thinks I am nuts when I tell him that I am a bit concerned that the new BMW turbo motors will need work north of 100k miles. His reaction is consistently along the lines of asking me how that is any different than any other car with over 100k miles that you want to drive and have 100% reliable for the wife and kids, etc. 100k miles doesn't sound like a lot, unless you drive a car new and take it to 100k miles. Then it doesn't sound so short.

Send this in to Roundel and the Mike Miller folks and their heads might explode. I think this month the E38 / M62 is the "whipping boy" in the tech talk column.

[Jeremy]

Mike Miller's head tends to explode every time he talks to us anyway.

Back to my earlier thought. We're telling all these new M5 owners to tend to their timing components. Should we just be telling the to replace the tensioner with the s5x version ASAP instead if they have no record of it ever being replaced?

Sort of like the m20 timing belt rule. If you don't know when or if it was done, put it at the top of your to do list.

Jeremy

[L_N_Love]

Mike Miller's head tends to explode every time he talks to us anyway.

Jeremy

[Mike W.]

I just think it makes good sense to refresh any motor every 100-125k, as I consider that to be normal maintenance. I hold reliability to be sacred as I drive these cars, so that is part of my thinking as well. Just my opinion.

It's funny reading the above -- this is what my father tells me about any car pretty much, and why he thinks I am nuts when I tell him that I am a bit concerned that the new BMW turbo motors will need work north of 100k miles. His reaction is consistently along the lines of asking me how that is any different than any other car with over 100k miles that you want to drive and have 100% reliable for the wife and kids, etc. 100k miles doesn't sound like a lot, unless you drive a car new and take it to 100k miles. Then it doesn't sound so short.

Send this in to Roundel and the Mike Miller folks and their heads might explode. I think this month the E38 / M62 is the "whipping boy" in the tech talk column.

Cars have gotten so much better and longer lasting in recent years. Even most domestic stuff will go 200K without needing major engine work. (I'm still of the opinion A/Ts are the weakest link) So a $3-5K (or more) bill for turbos at 100K is out of line IMO. And BMWs in general will go well beyond 100K without fear of major failure, again A/Ts exempted. Yes, cooling systems are maintenance items, but they've gotten cheaper over the years, radiators are far less, without inflation adjustment, than they were 20 years ago.

[1st 5er]

Back to my earlier thought. We're telling all these new M5 owners to tend to their timing components. Should we just be telling the to replace the tensioner with the s5x version ASAP instead if they have no record of it ever being replaced?

Sort of like the m20 timing belt rule. If you don't know when or if it was done, put it at the top of your to do list.

Jeremy

This???

[chrism]

Yes, this.

The rails are a symptom. The tensioner is the cause. The chain will not slap around to hit the rails if the tensioner dosent loose pressure.

Back to my earlier thought. We're telling all these new M5 owners to tend to their timing components. Should we just be telling the to replace the tensioner with the s5x version ASAP instead if they have no record of it ever being replaced?

Sort of like the m20 timing belt rule. If you don't know when or if it was done, put it at the top of your to do list.

Jeremy

This???

[Mike W.]

So looking at the blow up it appears there are two tensioners, an upper and a lower, the lower being the same or similiar to regular M30's? And I'm assuming it's the upper that's the problem or both? And part #29 or more?

[rlomba8204]

I just think it makes good sense to refresh any motor every 100-125k, as I consider that to be normal maintenance. I hold reliability to be sacred as I drive these cars, so that is part of my thinking as well. Just my opinion.

It's funny reading the above -- this is what my father tells me about any car pretty much, and why he thinks I am nuts when I tell him that I am a bit concerned that the new BMW turbo motors will need work north of 100k miles. His reaction is consistently along the lines of asking me how that is any different than any other car with over 100k miles that you want to drive and have 100% reliable for the wife and kids, etc. 100k miles doesn't sound like a lot, unless you drive a car new and take it to 100k miles. Then it doesn't sound so short.

Send this in to Roundel and the Mike Miller folks and their heads might explode. I think this month the E38 / M62 is the "whipping boy" in the tech talk column.

Cars have gotten so much better and longer lasting in recent years. Even most domestic stuff will go 200K without needing major engine work. (I'm still of the opinion A/Ts are the weakest link) So a $3-5K (or more) bill for turbos at 100K is out of line IMO. And BMWs in general will go well beyond 100K without fear of major failure, again A/Ts exempted. Yes, cooling systems are maintenance items, but they've gotten cheaper over the years, radiators are far less, without inflation adjustment, than they were 20 years ago.

I understand your point, but if you want a dry motor, at the very least my father's point would be that the engine should be gone through -- seals, etc -- at or above 100k miles.

I agree with you about the turbos. I wouldn't own one, primarily for that reason. But that's forced induction.