heinzboehmer's 2002 Topaz 6MT Coupe

[Bry5on]

Yep! Think Ted cracked the code. BCD makes total sense.

Funky implementation though. I know these are tiny (in terms of compute) embedded devices operating in a very constrained and well defined environment, but the complete lack of validation for most of the stuff on this bus is wild to me.

It was written in the mid-90s after all…

[heinzboehmer]

I don't want to start randomly throwing parts at the problem though, so I'm gonna rig up a pressure tester and grab some data first. Pretty sure I have a spare oil fill cap somewhere, so should just be a matter of drilling and tapping a hole for a pressure gauge. Stay tuned.

Coming back to this.

I did not, in fact, have a spare cap in the stash, so I ordered a cheapo one.

Turns out the cheapo cap is hollow inside:



Slathered a bunch of RTV on the threads to try and salvage this attempt:



But I'm not at all confident that it will seal. Think it's highly likely that the next update on this effort involves a CAD screenshot of a custom cap with NPT ports on it.

I'm seeing this more and more, somehow the timing chain tensioner starts to leak through the crush washer. I don't understand the physics of it, but I've replaced a bunch of tensioner crush washers recently.

The best part is that I replaced that crush washer a year or so ago because it was leaking

If that crush washer ends up being part of the problem, I'm not sure how I'm gonna fix it.

Maybe machine a groove in the tensioner to seal with an o ring instead?

Edit: I wonder if the uptick you're seeing is because most cars are no longer on the original crush washer and torquing the tensioner to spec in the engine bay is not easy?

[George Hill]

The best part is that I replaced that crush washer a year or so ago because it was leaking

What brand?

Edit: I wonder if the uptick you're seeing is because most cars are no longer on the original crush washer and torquing the tensioner to spec in the engine bay is not easy?

You may be right. I've installed thousands (?) of crush washers and I can generally "feel" them crush. I've also reused them, without issue, but if they aren't getting crushed fully or are reused then maybe?

Its actually super easy to torque with the right setup: 3/8" flex head, 3/8 - 1/2 adapter, 32mm socket. Tons of room.

[Obioban]

What brand?

Have your seen a variety of results based on crush washer brand? That always seemed like a safer area to cheap out (just a circle of copper), not that I've actually been able to sell myself on doing it.

[George Hill]

Have your seen a variety of results based on crush washer brand? That always seemed like a safer area to cheap out (just a circle of copper), not that I've actually been able to sell myself on doing it.

Not specifically, but I have replaced many non-OE crush washers that were leaking, I just don't know if it was a prior install error or part issue.

I have reused drain plug crush washers... a lot in the past with no know issues.

I'm not going to claim to be a metallurgist but its my understanding most BMW crush washers are aluminum is they are silver and copper if they are copper colored.

Now that I type this out it seems like BMWs are either copper M12 and smaller and silver/aluminum M14 and larger? As it relates to an S54, example:

• Copper - Drain plug, valve cover drain liner, vanos accumulator line, etc
• Silver/Aluminum - Tensioner, P/S Hoses, Rocker arm plugs on the back of the cylinder head, coolant drain plug, Upper T/C rail pin,

I have used aftermarket crush washers with success in the past, but they are generally so cheap I almost exclusively use Genuine now.

In this situation, 07119963418 is the T/C tensioner crush washer. On ECS:

• Genuine - $1.99, aluminum
• Elring - $2.03, copper

[Obioban]

Not specifically, but I have replaced many non-OE crush washers that were leaking, I just don't know if it was a prior install error or part issue.

I have reused drain plug crush washers... a lot in the past with no know issues.

I'm not going to claim to be a metallurgist but its my understanding most BMW crush washers are aluminum is they are silver and copper if they are copper colored.

Now that I type this out it seems like BMWs are either copper M12 and smaller and silver/aluminum M14 and larger? As it relates to an S54, example:

• Copper - Drain plug, valve cover drain liner, vanos accumulator line, etc
• Silver/Aluminum - Tensioner, P/S Hoses, Rocker arm plugs on the back of the cylinder head, coolant drain plug, Upper T/C rail pin,

I have used aftermarket crush washers with success in the past, but they are generally so cheap I almost exclusively use Genuine now.

In this situation, 07119963418 is the T/C tensioner crush washer. On ECS:

• Genuine - $1.99, aluminum
• Elring - $2.03, copper

FCP has a $0.59 option
(again, I've only used OE on my car, because because the price diff isn't worth the potential headache)

[bigjae46]

Not specifically, but I have replaced many non-OE crush washers that were leaking, I just don't know if it was a prior install error or part issue.

I have reused drain plug crush washers... a lot in the past with no know issues.

I'm not going to claim to be a metallurgist but its my understanding most BMW crush washers are aluminum is they are silver and copper if they are copper colored.

Now that I type this out it seems like BMWs are either copper M12 and smaller and silver/aluminum M14 and larger? As it relates to an S54, example:

• Copper - Drain plug, valve cover drain liner, vanos accumulator line, etc
• Silver/Aluminum - Tensioner, P/S Hoses, Rocker arm plugs on the back of the cylinder head, coolant drain plug, Upper T/C rail pin,

I have used aftermarket crush washers with success in the past, but they are generally so cheap I almost exclusively use Genuine now.

In this situation, 07119963418 is the T/C tensioner crush washer. On ECS:

• Genuine - $1.99, aluminum
• Elring - $2.03, copper

In the oil and gas industry, we carefully inspect any seal or gasket. The worst are the metallic spiral wound gaskets. Any nick, gouge, or damage renders the gasket defective. In that case, a leak at minimum causes expensive rework and downtime. At worst it causes a large release of highly flammable material.

I'd inspect those crush washers. I'm sure they are not handled carefully from the manufacturer to distributors to retailers to end user.

[George Hill]

FCP has a $0.59 option

Either way I wouldn't pick a $0.59 aftermarket part EVEN if it was labeled OE over a $1.99 genuine part.