Exhaust Manifold sealant - Yes or No?

[jedwards]

Gentlemen,
I have an early 250SL and I am about to reattached the exhaust and inlet manifolds following a bit of tidying up work and wondered if a gasket sealant is recommended?
In the past I have always used a thin layer of high-temp sealant to both the head to gasket and gasket to manifold  interfaces but what is the view of this august group?

[jameshoward]

We're both doing the same job. I don't plan to use a sealing compound. The gasket is pretty soft and should be fine.

Can you tell me if you've broken the code on the washers? Where do you plan to employ those wavy washers? I can't make head or tail of it. You'll see my thread with a similar title from yesterday. I'd appreciate your view.

James

[jedwards]

Sorry James,
I cannot help you on the washer issue. Mine is a 250SL and I had no such washers installed when I dismantled nor included with my new gasket set.
Sorry I cannot be of more help.
Jeff
 

[jameshoward]

OK. But you'll have the same issue as me, because the parts are common to all cars, including the 250sl. So if you don't have them on the car, it would suggest that the last person who did the job didn't use the correct parts. (I've checked the EPC for the 250 and it does show the wavy washers (x3) as being part of the assembly)

FWIW, I don't think it's worth dieing in a ditch over, but it would be great to figure out where these parts are supposed to go on our cars.

I'll let you know if I get to the bottom of it. Otherwise, we'll just crack on!

[jedwards]

Thanks James, I'd appreciate it

[jameshoward]

Here's your answer, posted in my thread. I'd suggest that you ensure that you use the correct nuts, washers and wavy washers as shown in the EPC. I can post the PNs if you need them. Common to all pagodas, I believe.

http://www.sl113.org/forums/index.php?topic=19278.0

[garymand]

Hope this helps: the manifolds have very thick washers on each stud.  the thick washers span the gap between the manifolds.  No gasket cement is needed.  I'm dure you know your exhaust manifolds are on backwards, you've got the thermostat housing and the chaintensioner nuts and washers to deal with too. 

[garymand]

also looking over the pictures on yours and the link: your head gasket is correct and it is pictured in the link as the lower used gasket.  the bright one is obviously for a different exhaust manifold with smaller ports than for a 250SL or 280SL.  I don't have experience on the 230SL, but I think it uses the same castings as in your pic.  If they were to re-use the old gasket then hightemp gasket cement would highly likely work well.  Mercedes, in many cases, the gaskets can be re-used if still in good shape, in a pinch.  I repeat, in a pinch.

[jameshoward]

Gary,

Yes, the pics in my link are indeed of the correct and incorrect gasket, with the dirty one being the correct one. That was a very obvious "oh, bugger" moment yesterday afternoon when I took both manifolds off. If I'd been slightly quicker off the mark I'd have realised this having looked at my replacement manifolds, but there we are. the correct gasket will be here tomorrow. The gasket that came off would probably have been OK, but for 10 euros and a 24h wait it was probably better to use a new one.

jedwards, on top of the washers, you'll also need 2 crush seals for the downpipe to manifold union. You'll see JA17's comments on my thread.

Hope that helps.