Thermostat housing bolt snapped - Page 2 - PeachParts Mercedes-Benz Forum

Orv · #16 06-15-2011, 10:17 PM

I don't know. Before I got around to a permanent fix, the engine mounts collapsed, and since the car was mostly made of rust and also needed front end work I decided to sell it for parts instead of repairing it.

layback40 · #17 06-15-2011, 11:08 PM

When you have a weak cooling system because of a broken bolt, the first thing to do is leave the radiator cap off. No pressure = smaller leak, gravity only.

Edit; dont leave it right off!! just dont screw it down. Pressure is your worst enemy with a leaky system !!

babyjames · #18 06-16-2011, 01:51 AM

Or PB blaster. Correct me if I'm wrong (like that WOULDN'T happen), but I think you can get at the ends of those bolts from the rear - they go all the way through the engine "half" of the housing?? If you can see the ends of the bolts, soak 'em down good and allow to sit overnight. Reapply the following day and then try to remove the remaining two bolts. Do you have a close-quarters drill? Milwaukie makes a cordless one that is a LIFESAVER! Very compact. I'll try to get out to the garage and have a look at the '83 tomorrow. R+R the housing may not be necessary. A great excuse to go buy a sweet new tool, to boot!

http://www.milwaukeetool.com/tools/cordless-tools/m12-cordless-system/m12-cordless-lithium-ion-3-8%27%27-right-angle-drill-driver-kit/2415-21

Jay

digieditny · #19 06-16-2011, 08:37 AM

I just looked! You are correct. There's about an 1/8th of the bolt sticking out the back. I should be able to grab it with a vise and hopefully remove it from the back. Ill soak them all overnight. Hope this works!

Hmm ya i don't have a close quarters drill. I should probably get it!

beermc00 · #20 06-16-2011, 10:44 AM

Hi,

I truly know your pain. I had the same thing happen to me last year. I ordered a used thermostat housing from a guy on ebay when it happened, but then found a good one at the local junk yard. Now have an extra that I was just sitting on for a rainy day, but I would be happy to send it to you for a reasonable price. When I think about it, I hope I'll never need it since I put anti-sieze on the one that is installed in my car now. Also, it really is easy to replace the whole housing, its basically two bolts and a hose clamp.

P.S. when it is all said and done, what-ever you choose to do, make sure you put the thermostat in facing the right direction, don't ask me why I am warning you of this. The engine will get awfully hot and you will have to take everything apart again...not fun!

Anyway, PM me if you are interested in the spare part I have.

Good luck!

digieditny · #21 07-10-2011, 06:51 PM

Ok so I'm going to tackle this job tomorrow... Going to replace the thermostat housing. I want to know if anyone has done this job with any trouble. I worry about bolts #46. I don't want them to snap off. If that happens, I'm screwed!

tq190 · #22 07-11-2011, 11:07 AM

I had this happened on the 240D I used to have. What I did was first remove the thermostat housing cover, put a nut has the same thread on the remaining portion of the broken bolt and tighten the nut and this pull the broken bolt out from the front. I would soak the broken bolt with PB Blaster overnight to break the rust bond.

Try this before drilling out the bolt. I tried to drill out the bolt but ended up breaking the ear of the housing which made the situation worse.

If you need a replacement housing I have one posted the Parts section of the forum.

Tan

'87 190D 2.5t
'87 300TDT
'92 300D 2.5t
'82 240D 4-speed (sold)

digieditny · #23 07-11-2011, 12:09 PM

Hey Tan. I appreciate the response. I have already purchased a thermostat housing. I'm just going to replace the whole housing. I live in an area where I need to move my car daily because of street cleaning. So I don't really have the option to leave the car sitting.

Did you have to replace the whole housing at any point? What worries me is bolt #46 (picture attached on post 21). I can't have those snapping on me. If you have removed the whole housing, did you encounter any issues with those 2 bolts? I'm going to soak them in PB blaster overnight hoping that they don't snap on me too. I'll go take a picture of the bolts now to show you which ones I'm talking about. Thanks!

tq190 · #24 07-11-2011, 12:32 PM

Bolts #46 are much bigger/stronger bolts than the three 10mm bolts on the cover. I doubt you will have a problem with them. You will need to replace the paper gasket #49 goes on the engine head.

Tan

'87 190D 2.5t
'87 300TDT
'92 300D 2.5t
'82 240D 4-speed (sold)

digieditny · #25 07-11-2011, 12:35 PM

Yep I've got the paper gasket from fastlane. Have everything I need. Here's the picture I promised. Pre-PB blaster soaked picture... 2 left most bolts. Very rusty...

digieditny · #26 07-11-2011, 05:03 PM

Ok all finished. Was an easy job. Took about an hour. The most trouble I had was getting the paper gasket to stay put.

The thermostat and the o-ring that I replaced looked pretty new. We'll see if I continue to have overheating problems.

Thanks for your help everyone!

nhdoc · #27 07-11-2011, 09:23 PM

You should always use anti-seize when you replace those bolts...then next time you won't go through the struggles you did now to get them out

Orv · #28 07-11-2011, 11:31 PM

Quote:

Originally Posted by digieditny

Ok all finished. Was an easy job. Took about an hour. The most trouble I had was getting the paper gasket to stay put.

Well done!

With paper gaskets I like to use "aviation sealer," also known as "Permatex No. 3." It's thin and brushes on, and if you leave it for a couple minutes it'll get tacky and stick the gasket in place. It stays tacky forever, never really completely hardens (as I found out the hard way when I spilled some in my toolbox!) Unlike the orange stuff it won't interfere with a close fit and can't squeeze out and form blobs inside the housing.