i just experienced an overheat issue with my 1986 740 wagon with the b230 n/a engine. apparently while getting stuck in snow and revving the engine a bit the heater control valve blew losing all my coolant. i let it cool at gas station for a bit than it overheated again. i was only about a mile out of town where i live and so i drove it back to the station(about 1/4 mile or so in the way red. gas attendant gave me a bucket of straight water because i had no coolant and it poured right out indicating the heater valve problem. i put 2 and 2 together no heat coolant loss and sure enough valve was destroyed.

my main concern here is: is there any possibility of other engine damage? the engine ran fine once the water was added and got me home untill it just went red again. it idled like it was not overheated either i should add and starts right up. since its 19 degrees outside the engine did cool off quick and valve will be replaced tomorrow.

do i need a head or anything else?

geoff

Hi,


When the needle is in the red, engine damage is occurring.

If the combustion gas starts exiting through the coolant reservoir or there is a cloud of white smoke when you start it up, you know that the cylinder head warped. Transverse warpage is measured in thousands of an inch. It doesn’t take much to destroy the gasket seal.

Fix the car and see how it runs, you‘ll know soon enough. But the next time, be sure that you stop and let it cool before it gets to the red!


Goatman

thanks goatman,

yea it seems ok but we shall see when i fill it back up and valve is replaced. wouldnt be the first time its gotten into the red im just praying bc im in wi and the junkyard i used to deal with when i was in nj(its in pa) is kinda far to take advantage of thier 75 dollar u pull engine deals(last i checked in 2008)

yea try telling cop that car needs to cool off lol but i was glad that it was right near the citgo:) how long can the head take before it starts to warp? it did steam alot but im praying i shut it off in time.

Hi,


I have had to pull off and cool down before. Add water (always on board), and see what the heck is going on. I was asked by the police, he said he could call for a tow if I needed. Very nice and polite.

Don't be afraid of the police.


Goatman

lol goatman yea im not afraid of them and officer meyers in town here is one of the most friendliest of the force. he was just like hurry up bc youre blocking northbound traffic so i hurried it into the citgo hehe. in any terms i did manage to get valve replaced and so far looks like nothing else got damaged. i will know soon as i get another gal. of antifreeze(only one in there so far forgot to ask pastor if it was straight or 50/50 but im thinking the latter of the two) lust the pump gasket to head is leaking a bit again im wondering if i should put some bars in there to get it to stop just for time being.

I went thru an identical scenario a couple months ago. Only one way to tell. Fix it fill it run it and keep your fingers crossed. Monitor coolant level carefully for next couple thousand miles. Mine has showed no evidence of HG damage, good luck. BTW those stupid valves are P.O.S. they should be on a 30,000 mile replacement schedule IMHO.

thanks mmal,

fortunately i can get some antifreeze from my pastor in town(hopefully it dosent burn out the rear end lol). is there a straightforward replacement trick for the valve? i tried getting ahold of it but since everything is so darn crammed in there im wondering if i need to remove any cables.

ok remedied everything is buttoned up valve is replaced and no coolant leaks(at very first some minor cylinder head to water pump gasket"o-ring" leak but it stopped without the assistance of any bars or sealant) engine runs fine and head gasket is a-ok. thanks for all the help everyone:).

now to talk with the wrecking yard down the street from me. hes got a nice newer maroon volvo that engine or trans is shot that if its got a title ill try to pick it up from him(complete of corse) for a couple hundred:)

The FAQ describes the valve replacement. Get an OEM Volvo heater valve: yes, they are much more expensive ($40 vs $15) but the quality is vastly better than aftermarket. Buy from Tasca or Borton Volvo.
How old was your old valve, btw?

And on the engine: IF the headgasket is shot, you will most likely notice by doing a coolant fluid exhaust gas check. Your local mechanic can do this very quickly and inexpensively: he tests for exhaust gases in the fluid. And watch your oil VERY carefully and frequently: if coolant should get into the oil, it will show up as a milky brown mix.

@ steve,

it was the original valve i did not take advice BEFORE the incident occured but i did have a new aftermarket cheapie i got few years ago and threw that in just untill i get the money for the volvo one. i knew it was the orig. one bc it broke off and i could give the heater tube a slight squeeze and the nipple busted up of corse being careful to make sure all remnants were clear before reinstalling new valve. 1 gal of antifreeze in it now i forgot to ask my pastor if it was 50/50 mix though so im assuming it is.

so far so good valves did tap a bit but it dosent blow white smoke. gotta change my oil soon anyhows so ill be checking for the antifreeze when thats done. im just keeping my fingers crossed for now.