Throttle housing heater/coolant hose plate, again!

So, that little square plate on the throttle housing coolant warmer thingy, that gets its cork gasket blew again during an inspection/emission test on the dyno (Thank goodness as of the 1st of the year I will not have to put my car through anymore in new york). I replaced that little cork gasket, and faced off the housings a few years ago and already it's leaking again!

Now, other than the cooling system is building up too much pressure, I can't think anything is wrong; car runs cool and there are no leaks, other than a touch of topping off after 1000 miles or so after a hard run.

This is one thing that bothers me, all my Thirtys have never, ever needed topping up... ever. About a year or two ago I noticed the coolant level down a touch every so often but never found any leaks..... I know, head gasket?, well, there's no sign of that and nothing on the floor ever so until I see something I'm going to take it as it comes,but this housing gasket, I don't know if the stock cork gasket is the best style gasket I want in there, maybe a thinner gasket material type gasket would serve better

I'm going to order a new cork one (even for a templet) and take it apart and see what gives, who knows, maybe the housing is cracked...

Rick



perseverance furthers

For what it is worth, I just went thru all this hand wringing on my wife's PT Cruiser. I was losing coolant and was terrified it was a head gasket or cracked head. Turned out it was the $3.50 radiator cap. A buddy lent me a pressure tester. Engine tested fine, cap wouldn't hold a weak fart in a windstorm (how's that for a visual). New cap, no coolant leaks.

Is the gasket on that plate supposed to be cork or neoprene? Could that be the problem, wrong material?

alan

Quote
alanrw
For what it is worth, I just went thru all this hand wringing on my wife's PT Cruiser. I was losing coolant and was terrified it was a head gasket or cracked head. Turned out it was the $3.50 radiator cap. A buddy lent me a pressure tester. Engine tested fine, cap wouldn't hold a weak fart in a windstorm (how's that for a visual). New cap, no coolant leaks.

Is the gasket on that plate supposed to be cork or neoprene? Could that be the problem, wrong material?

alan

It's supposed to be cork, and it's fairly thick. I keep on thinking it's weak my cap is original

Thanks Alan

Hmm, wonder why it's not a more modern material?

alan

Quote
alanrw
Hmm, wonder why it's not a more modern material?

alan

Kinda surprised me to.

Quote
rkj

Quote
alanrw
Hmm, wonder why it's not a more modern material?

alan

Kinda surprised me to.

My guess is that since the small coupling block is only held on by two or three small torx screws; that the gasket needs to be semi resilient to handle the constant expansion and contraction that goes on there. Unlike head bolts or water pump bolts, there is only limited torque that can be applied to those screws.

Also, since the E30 has been out of production for at least 17 years, I wouldn't expect BMW to have upgraded such an insignificant part.

Making a new gasket out of a more modern material shouldn't be that big a task; I'm sure Rick has made many a gasket in his time

Quote
Archeo-peteriX

Quote
rkj

Quote
alanrw
Hmm, wonder why it's not a more modern material?

alan

Kinda surprised me to.

My guess is that since the small coupling block is only held on by two or three small torx screws; that the gasket needs to be semi resilient to handle the constant expansion and contraction that goes on there. Unlike head bolts or water pump bolts, there is only limited torque that can be applied to those screws.

Also, since the E30 has been out of production for at least 17 years, I wouldn't expect BMW to have upgraded such an insignificant part.

Making a new gasket out of a more modern material shouldn't be that big a task; I'm sure Rick has made many a gasket in his time

Yup, I've made a few gaskets, although this one is especially small and complicated, but the fact that it keeps blowing out leads me to believe the cork is not strong enough. I ordered a few up this morning and Monday I'll see what is going on first hand

Thanks Guys

And the threads on the body part are in good shape? We haven't heard of many people having this problem which leads me to think perhaps the screw fasteners on yours are failing?

alan

Quote
alanrw
And the threads on the body part are in good shape? We haven't heard of many people having this problem which leads me to think perhaps the screw fasteners on yours are failing? Helicoils?

Was this part common to all E30's 84-9x?

alan

Quote
rkj

Quote
Archeo-peteriX

Quote
rkj

Quote
alanrw
Hmm, wonder why it's not a more modern material?

alan

Kinda surprised me to.

My guess is that since the small coupling block is only held on by two or three small torx screws; that the gasket needs to be semi resilient to handle the constant expansion and contraction that goes on there. Unlike head bolts or water pump bolts, there is only limited torque that can be applied to those screws.

Also, since the E30 has been out of production for at least 17 years, I wouldn't expect BMW to have upgraded such an insignificant part.

Making a new gasket out of a more modern material shouldn't be that big a task; I'm sure Rick has made many a gasket in his time

Yup, I've made a few gaskets, although this one is especially small and complicated, but the fact that it keeps blowing out leads me to believe the cork is not strong enough. I ordered a few up this morning and Monday I'll see what is going on first hand

Thanks Guys

Hi,

Not that I really know very much about this topic, but my cork gasket failed about two years ago. Beemie also had a failed coolant level sensor which was quickly replaced. One potential disaster avoided.

Cheers, Kelly

As for your coolant level dropping in general but with no telltale green puddle, I have heard of these causes:
- leaking onto exhaust manifold, so it's boiled off
- only leaks when pressurised, so put a pressure tester on it overnight

Cheers,
Simon

Quote
nomis3613
As for your coolant level dropping in general but with no telltale green puddle, I have heard of these causes:
- leaking onto exhaust manifold, so it's boiled off
- only leaks when pressurised, so put a pressure tester on it overnight

Cheers,
Simon

I should invest in a pressure tester for the Bmw's for sure. Nobody I know has one either I'll have a good look when I'm in there doing the throttle body coolant thingy, I still have a few original hoses too, hell, they're only 235k old! I bought a hose kit a few years ago but was too lazy to put all of them on ....bad rick.... they all still looked in good shape though with a few cut back ends.

Yeah, it's spooky not knowing where the hell that missing coolant is going, I hate that!

Thanks, Rick

Quote
alanrw
And the threads on the body part are in good shape? We haven't heard of many people having this problem which leads me to think perhaps the screw fasteners on yours are failing?

alan

Actually the screws are fine, I took everything apart today and it all looked good. I had put luberplate on the screws so those were fine, came right off. Everything looked intact (just did this 2 years ago) but this time I put the cork gasket in there dry (last time I put a thin coat of atv on everything), I remember for the old days cork gaskets work better dry. Lets see where this gets us.

I think while it's apart I might as well take that barrel plug apart and see how that's fairing too (while I'm in there), shit, that should be on my tombstone...

Come to think of it I should have replaced the cap, the pressure might be building up in the system and punching that cork gasket out dam, I wish I had a tester!

I looked that water housing over real well and it seemed tight so back in it went, all the hoses are also in good shape....

Here's hopen

I don't think I have ever seen a radiator cap fail in the "too much pressue" mode, usually they fail because they can't hold pressure.

alan

Quote
alanrw
I don't think I have ever seen a radiator cap fail in the "too much pressue" mode, usually they fail because they can't hold pressure.

alan

Oh good, that should be easy to check for. Thanks Alan. All went well; new cap and wires, trigger wire in place. Cleaned the barrel connector under the intake (wasn't dirty at all) but the wires can be bad coming off the connector under the covering so I don't know and can't see those!

There's a few storms coming so maybe I'll just keep him inside and get to that fuse box tomorrow, right now just busy with some cleaner/wax.... This is nice here