Ugh...I just found rust. What is this part?
 

My '86 930 didn't have any rust on it... until I was putting some grease on the rear deckled latch and found some. I hate it when that happens.

I don't think this is on the body/chassis of the car, it looks more like a pan (surround?) around the engine. I don't think it is the engine mount/brace. What is it? How hard is it to get to? Should I worry about it immediately (or can I wait a few months)? Will the rust 'grow' if the part stays dry (don't drive in the rain)?

(The pic is from the driver side, looking back towards the bumper. The engine mount is on the right, with the large black pipes on the left for the intercooler.)

Looks like the rear shelf - which is part of the chassis...

-Wayne

Looks a lot like the rear engine support to me.
BTW you may want to replace some rubber there.
GeorgeK

It seems to be looking back towards the rear bumper. That's the sticker advising timing/idle etc in the upper middle of the shot.

It is hard to tell but it looks like the engine tin got hot from the turbo and the paint came off. It looks like surface rust on the tin and the rubber seal is torn. If that is the case then you should fix the rubber seal, so the fan doesn't suck hot air.

If it's just surface rust clean it up and get some POR-15 on it then spray it with some touch up paint. Blown is right, replace the seal so you don't pull hot air back into the engine bay.

That's not too bad, it looks like rust on the engine tin. You'll need to drop the motor to replace that seal and get to the piece that needs to be painted, maybe a partial engine drop would do it.

Boy if that's all the rust you got Your a Lucky man! POR 15 It Like Jadams said

Thanks for the help (and words of encouragement). Being from Southern California, the slightest bit of rust scares me. Come to think of it... even rain scares us!

POR-15, and a new gasket it is.

Help me! It might rain today!! Will we melt??

I wouldn't be too worried about the rust yet. It's surface rust and I would just take care of it at the next opportunity. Of course that seal may be just the opportunity you need.

Maybe SBRI & engine drop clinic on Feb 8th?;)

I'll look tonight, but I think that area is very close to the turbo which puts out alot of heat. On my '86 930 with just 6k miles I have some surface rust right around there, very close to the turbo. If it's the piece I'm thinking of, it is just very thin tin which has a matt paint on it. I don't think I've ever seen a turbo without some rust around there. Hope this helps.

Chris

It is just above the turbo. That piece of metal can easily hit 400 F. (so paint doesn't really stand a chance unless it is BBQ-ready).

On mine, I wonder how long it has been there... I'll feel much better knowing other 930's have it too.

they all rust the tin down there. that's a difficult piece of tin to remove on a 930, so best to deal with it in the car.

Emission,

I just checked my car and there is rust in the same place as on yours. Most of the paint is still on that tin piece but where it is flaking there is rust underneath. I've noticed this before and just chalked it up to the high temps in that area. I really wouldn't worry about it, and I worry just about everything.

Thanks to all with 930's who share my pain (rust). Now that my pulse is back to normal, it doesn't seem that my engine will fall out tomorrow. Whew.

If, and when, I tackle the repair... I'll post procedures and pics. Please do the same if you get to it first.

Regards.

shot motor mount
 

Don't know about the rust but that motor mount is shot!

Re: shot motor mount
 

That goes on my (ever growing) list. This is my first used car since I was in High School. I never realized how long the 'List of things to do' could get!

Re: Re: shot motor mount
 

Amen brother:p

Hi,

What you see rusted is only the rear engine tin -- not structural. I agree with others that the heat from the turbo and exhaust has cooked to paint off. While the tin is held on by only a few small screws, it is a real pain to remove and replace because of all the pipes that run through it, and also because it is behind the engine mounts. So I would leave it alone until the next time you have to remove the engine. I recently did some work on my 930 engine, and while I had all the engine tin off, had it powder coated. Hopefully, the power coat will hold up to the heat...

At any rate, the slightly bigger problem that you might be concerned about is the chipped rubber road seal that you see there in the picture. Since it is broken, some air from under the engine will get sucked up through the space, and potentially cause your heating air to smell. That was the case in my 930. I think you might be able to replace that seal without removing the engine entirely, although I believe that you will have to lower the rear of the engine down enough to access the seal. I replaced the seal while the engine was outside of the car.

-Juan

I am getting a strange exhaust-type smell in the car under hard acceleration/RPM. I wonder if it is from that broken gasket?

Like the others said, the surface rust on the tin is a big nothing, but the rubber seal is not. I learned back in my VW days that the rubber/tin seal is crucial to the cooling of these engines! Without a tight seal around engine bay, fan is sucking super-heated air and just recirculating it. With 930's excesive heat in that region, I would imagine that they go through that seal pretty regularly, but I would still replace it whenever neccesary.

It would be a real easy DIY job to do a partial drop, (2 bolts and a floor jack w/ a piece of plywood), replace the seal and the motor mounts at the same time. Where are you in So. Cal.? Maybe I could come down and help you if you need it, drop me a line. :cool:

Edit: Just looked at your ID, Thousand Oaks is close enough to me.

If you are getting exhaust smell in the cabin under boost I think you have a cracked heat exchanger.

So, is this the part I need to replace to fix that gasket?

Engine Sheet Metal seal, 3-sided, 911 Turbo (1976-89)
H-504-170-01 $136.00

I also need two engine mounts...

I don't think the heat exchanger is broken since I don't get any exhaust smell in the car when the heat is on, only when it is under high boost.

Like I said if you get exhaust smell with the heat on under high boost I think you have a cracked heat exchanger

OK, I don't count anything out.

Do I need to pull the exhaust to check? If it is cracked, is this the perfect excuse for a full B&B? Oh, my wife would kill me...

Mine are cracked also and I am going to go with SS heat exchangers. You could tell the wife that it is a safety issue. CO is very bad

I just thought of an easy way to check. I have a home CO detector/alarm that is battery operated (just like a smoke detector). I think I will need to pull it off the wall and take it for a ride with me!

My car is out of commission for a pedal re-build right now. I will post my findings this weekend. Thanks for the insight!

That might work. You could also go to your local fire dept. and get a fireman to ride with you while he is reading a portable CO meter. You will have to scare the hell out of him, but that's ok.

Hi Emission,

> So, is this the part I need to replace to fix that gasket?
>
> Engine Sheet Metal seal, 3-sided, 911 Turbo (1976-89)
> H-504-170-01 $136.00

Yes, exactly. There is also a seal along the forward side of the engine too, but it almost certainly in good shape, because it doesn't get cooked.

Regarding exhaust smell, how exactly does it smell? Does it make you dizzy, i.e. CO? Or is it more like gas/oil fumes? If it's just gas/oil fumes, then it would not be a problem with the exhaust system.

I agree that exhaust smell would point to a problem with the heat exchanger. However, another possibility is a broken exhaust gasket or cracked exhaust pipe, combined a way for those fumes to get sucked into the fan, i.e. your cracked road seal. One of the problems that I discovered when I worked on my 930 engine recently was an exhaust gasket that had burned through, which was presumably allowing gases to escape at the flange.

Does the smell happen when the heat is turned off? Fumes from a crack in the heat exchanger, or getting sucked into the fan, would be worse when the heating system is on.

I like the idea of using a home CO tester -- good idea!

-Juan

I can only smell it under full boost, with or without the heat. I rarely run the heat, so I know it happens just as often with the heat off.

Originally, I thought the smell was along the lines of raw fuel... but then, as I started to really think about it, it started to smell more like a fuel/oil mix. It does not smell like it is burnt, nor does it smell like exhaust. I am getting a fuel mixture sensor, so I will be able to see if it is running too rich under boost.

Tomorrow, I will be under the car replacing the clutch cable. I will get a chance to check out the exhaust at that point. I am going to start a new thread on this (this is getting off the original topic).

Thanks so far!

Hi,

> I can only smell it under full boost, with or without the heat. I
> rarely run the heat, so I know it happens just as often with the
> heat off.
>
> Originally, I thought the smell was along the lines of raw fuel...
> but then, as I started to really think about it, it started to smell
> more like a fuel/oil mix. It does not smell like it is burnt, nor does
> it smell like exhaust. I am getting a fuel mixture sensor, so I will
> be able to see if it is running too rich under boost.

If the heat doesn't affect the intensity of the smell, then I would say it is not related to either the road seal or a possible leak in the heat exchanger, or exhaust system.

So, I have a similar sort of smell in my '86 930 as you describe -- a sort of stale fuel smell. It doesn't smell as sharp as fresh fuel. Actually, the smell is a lot like what you smell if you put your nose up to the fuel hoses in the luggage compartment, just foward of the brake servo. The smell is most noticable when you open the sunroof. I suspect some kind of fuel leak, but haven't narrowed it down. Does this sound like your problem?

My '85 Carrera had a fuel smell that turned out to be a leaking fuel line at the front pump. It puzzled me for a whole year, until one day it finally failed enough to drip gasoline on the ground right under the pump, which exposed the problem.

-Juan

It does smell like stale fuel - the same smell the car fills the garage with when it is parked after a hot run. I keep thinking it is fuel related - especially considering I smell it under hard boost.

The CO you will never smell...until too late. Many people perish every year from bad stove/water-heater mixtures (a yellow flame is dangerous-too rich). The symtoms are dizzyness and nausea in small qualtitys. The burning nose is from HC's which are raw gas.
That smell could be from raw gas in the hot tailpipe from a way over-rich mixture/misfire under full load if not something else.
Just remember-"Rust never sleep's". put some rust converter on it if nothing else.