Seta cam gear fail--Anyone heard of this?

[TrentW]

So my wife's car is an '88 Seta sedan with a production date of 9/87. Supposedly there are two different cam sprockets on early production Seta engines--a cast or a stamped type. The word is the stamped type can break--and we all know what happens then--so it should be replaced w/the cast type. What pisses me off is that I just recently did the belt, tensioner, cam seal and water pump on this car and I really don't want to have to open up the patient again unless absolutely necessary.

Does anyone know if this is a legitimate issue with these sprockets?

If so can I remove the valve cover and determine which type of sprocket I have?

[e30rapidic]

you won't be able to tell from pulling the valve cover. You'll need to remove the distributor cap, rotor, etc to see the cam sprocket.

[GOOBER]

There's a legitimate issue with them...ask me how I know I had less than 3000 miles on a recently done head gasket, timing belt, tensioner etc when my motor decided to eat itself.

The stamped metal one has a design flaw (my seta was built 9/87 so the early setas definately have them). The later model engines had the cam gear made of cast metal. Mine sheared apart and the valves made contact with the pistons...head was trash, the pistons were salvagable though.

Here's a thread I started about it on e30tech a few months ago.

http://e30tech.com/forum/showthread.php?t=87184&highlight=cam+gear+blues

[GOOBER]

Here's the pic of what my cam gear looked like. I have to say though, I think part of the reason it gave was because I did the "i' top and swap and the higher revs from beating on the car caused t to give. My reccomendation for anyone doing a "budget stroker" based on the seta is to get the cast gear - about $30 bucks new from the dealer. They don't make the stamped one anymore.

[SpecM]

^ wow that sucks

I've never heard of that happening before

[eugeman]

Someone mentioned this to me last week in response to my post, I'll sell you my "I" one for $10 if you are interested. Won't be till next week before I can ship it out though.

[MikeDE]

Or you could get an adjustable....there was a nice one on here a few months ago that was no more than $90. I just don't remember who sells it.

[TrentW]

There's a legitimate issue with them...ask me how I know I had less than 3000 miles on a recently done head gasket, timing belt, tensioner etc when my motor decided to eat itself.

The stamped metal one has a design flaw (my seta was built 9/87 so the early setas definately have them). The later model engines had the cam gear made of cast metal. Mine sheared apart and the valves made contact with the pistons...head was trash, the pistons were salvagable though.

Here's a thread I started about it on e30tech a few months ago.

http://e30tech.com/forum/showthread....cam+gear+blues

So by your pic it's the intermediate shaft gear and not the cam gear?

How can I identify if it's the stamped gear or cast one?

Either way it sounds like it's time to pull it apart again. Or I could just let it go, hope the pistons don't get damaged, swap in the extra "i" engine I have and turn my "is" into a stroker...;)

[GOOBER]

So by your pic it's the intermediate shaft gear and not the cam gear?

How can I identify if it's the stamped gear or cast one?

Either way it sounds like it's time to pull it apart again. Or I could just let it go, hope the pistons don't get damaged, swap in the extra "i" engine I have and turn my "is" into a stroker...;)

you can tell by a visual inspection, they're pretty easy to tell apart. The stamped gear is solid and the cast gear has "spokes" on it and kinda looks like a wagon wheel.

[TrentW]

So I stopped by to see my tech friend "Zen Ben" yesterday and asked him about this issue. Ben is one of the best and most knowledgeable techs in the country, especially on the older stuff. He said he's never heard of a single instance of this failure, ever. He said this is actually caused by a failure of the tensioner. I called another BMW tech friend today and he said the same thing. I then reread your post on E30Tech and realized that you didn't replace the tensioner with your belt. ALWAYS replace the tensioner. And the water pump and cam seal if you're not sure when they were replaced last.

I've decided to leave mine alone and not worry about it, but if anyone has any evidence that contradicts this theory, I'm sure we'd all be interested in seing it.

*If I'm wrong and my wife's Seta goes kablooey, well then I'm just gonna swap in the extra "i" engine I have in the garage and use the Seta lower end to make a stroker for my '89 325is. That's a win-win. :)

[GOOBER]

So I stopped by to see my tech friend "Zen Ben" yesterday and asked him about this issue. Ben is one of the best and most knowledgeable techs in the country, especially on the older stuff. He said he's never heard of a single instance of this failure, ever. He said this is actually caused by a failure of the tensioner. I called another BMW tech friend today and he said the same thing. I then reread your post on E30Tech and realized that you didn't replace the tensioner with your belt. ALWAYS replace the tensioner. And the water pump and cam seal if you're not sure when they were replaced last.

I've decided to leave mine alone and not worry about it, but if anyone has any evidence that contradicts this theory, I'm sure we'd all be interested in seing it.

*If I'm wrong and my wife's Seta goes kablooey, well then I'm just gonna swap in the extra "i" engine I have in the garage and use the Seta lower end to make a stroker for my '89 325is. That's a win-win. :)

See I agree with you abount me not replacing the tensioner but it was not the fail point here (the tensioner was perfectly intact and I replaced it with a OE one when I just rebuilt everything). The stamped metal has a design flaw, hence why the redesigned it on the later cars. I would replace it just to be on the safe side. But that's just me. Hope it works out for you. Good luck!

[nando]

the stamped cam gears are KNOWN to fail

I've seen several of them fairly recently. The stamped steel rusts and crumbles.

There is probably a reason BMW replaced them with much beefier cast steel sprockets

and sorry, but screw BMW techs, I've had "knowledgeable" guys tell me all kinds of idiotic stuff. :p

[GOOBER]

the stamped cam gears are KNOWN to fail

I've seen several of them fairly recently. The stamped steel rusts and crumbles.

There is probably a reason BMW replaced them with much beefier cast steel sprockets

and sorry, but screw BMW techs, I've had "knowledgeable" guys tell me all kinds of idiotic stuff. :p

Thank you! I thought I was losing my mind here.

[TrentW]

the stamped cam gears are KNOWN to fail

I've seen several of them fairly recently. The stamped steel rusts and crumbles.

There is probably a reason BMW replaced them with much beefier cast steel sprockets

and sorry, but screw BMW techs, I've had "knowledgeable" guys tell me all kinds of idiotic stuff. :p

I understand where you're coming from here, as I know of many of the same. However, it's ignorant to use a blanket statement like that when you don't even know who the fuck I'm referring to. Ben Thongsai has been an independent tech here in Chicago for a long time and has been referred to and featured in numerous publications. Google him and see what you find. Or ask blunt and see what he has to say. I'm sure he'll set you straight. It's entirely possible that Ben has never come across this sprocket failure, but that in no way justifies your prejudice re techs. And Ben's been a friend of mine for ten years now, so I call bullshit on ya.

[nando]

it wasn't really a comment towards your particular guy. More towards people who use the "I'm a SAE mechanic" or "I'm a BMW tech, biotch" line to prove that they know what they are talking about, when most of them don't have a clue beyond plugging in a diagnostics machine that tells them what's wrong.