This cool morning (40 miles in sub tropic zone) I noted the fan was blowing to the windshield vent not the center console vent and it was cool. When I came to a stop the warmer air came out of the console vent. I parked and shut off the engine and it took about five secounds to stop. I first checked all vacuum lines and connections with my $35 vacuum friend and everything seems fine, 22 hg out of the vacuum pump, all locks work.

Looked at the number on the monovalve 1147122012 and went on line to buy a rebuit kit from fastlane, worry about dieseling later. They do not list any kit but had two different monovalves for sale if you know which fits your car.

I of course, gave up and went back to see if it still will diesel. Five out of five times it stays on a few secounds after the key is off.

Do you thing there is a relationship or am I just looking for something to fix.
As well, anybody know where I get the monovalve rebuilt kit ?

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In scuba diving and skydiving as in life, if it isn't fun, your doing it wrong.

Original owner & daily driver, 1983 300SD 298,000 miles.

The monovalve controls the flow of coolant into the heater core. When the valve is fully open, full flow goes to the core and you get maximum heat. The monovalve is the first culprit when you don't get any heat. I just bought a kit on e-bay for $20.00. They are on there every week.

The monovalve has nothing whatsoever to do with the vehicle taking five seconds to shut down. This is likely related to the vacuum shutoff on the back of the IP. See if you can shut the engine down with the Mityvac. If it shuts right down, then, your problem is in the supply of vacuum to the shutoff. You might have low vacuum in the system, or the key switch is not functioning properly. Track it down with a vacuum gauge.

You are right about the vacuum leak Brian, I went back and ckecked the connection under the car to the tranny and pushed the vacuum hose deeper into the connector, and then tested the shut off time back to zero. I Look on ebay for the monovalve kit and at $40 and two days to go. I then sent an email to phil at fastlane if he could get them. Meanwhile, it is back in the 70's so I can wait for the email without the heater.

THANKS AGAIN

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In scuba diving and skydiving as in life, if it isn't fun, your doing it wrong.

Original owner & daily driver, 1983 300SD 298,000 miles.

Maybe I am confused, maybe I am being dense...
Why do you think you need a monovalve (or monovalve insert)? Are you getting too much heat, or not enough heat?

Too much, would indicate a failed insert. Not enough, would indicate the fixture itself is not operating the way it should. Before you take out your wallet, check the connections on top. I recall a post from years ago, where a member merely had filthy connections, and was able fix his trouble without spending any money.

Hope this helps..

-Larry

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7952049394&category=33548


Monovalve kit.

$20.95.

Buy it now.

Help is what we do here.

For reasons that are not immediately known, I had zero heat with a failed monovalve diaphragm. You would think that this would result in unlimited heat, but, it does not.

Brian,
Thank you for the link, I ordered the monovalve. However, when I tried to find that monovalve on Ebay motors I would only get the $40 items. What do you known about ebay search that the rest of us don't?

Thanks again for your help.

__________________
_____________________________

In scuba diving and skydiving as in life, if it isn't fun, your doing it wrong.

Original owner & daily driver, 1983 300SD 298,000 miles.

I did too. I think the thing stuck or something. Unfortunately, mine failed a long time ago when I knew so little about the car that I actually PAID someone to work on my car and didn't see the component myself - think it was in 98. Except for a bit of engine machining, that was the last time

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

I find a lot of parts on e-bay by just browsing the "Mercedes Benz" parts listing. Granted, its about 50 pages long, but, I only look at the first ten pages. You find things that don't show up in a search. In this specific case, you cannot find it using "monovalve". He listed it as a "heater valve". So, you miss it.