| Author |
Message |
Verell Boaen (Verell)
Member
Username: Verell
Post Number: 984
Registered: 5-2001
| | Posted on Monday, July 21, 2003 - 8:39 pm: | |
It doesn't take much trapped air in a 3x8 for the engine to start running warm.
AIR BLEED PROCEDURE
-------------------
3x8s have 2 coolant bleed locations.
1)A straight knurled disc wheeled valve on the rear of the passenger side of the radiator.
2) A brass hex-head bolt on the thermostat housing.
With the engine cool (ie: system unpressurized), do the following:
1. Open BOTH heater valves (temp levers set to max RED.) (Heater cores just love to trap air!)
2. Remove the coolant reservoir cap. Make sure the coolant reservoir is properly filled. (Keep a container of 50-50 coolant:water mix handy, you'll have to add some as you bleed air out.)
3. Hold a paper towel under the radiator bleed valve & Open the valve. You'll probably get a hissing sound & maybe small bubbles as the air bleeds out. It's time to close the valve when it stops bubbling & begins peeing a thin stream.
(It's desirable, but not mandatory, to jack the front end up 8" - 10" or so while doing this step. Then let it back down before you go to the next step.
4. Use an 8mm hex wrench to unscrew the bleed bolt on top of the thermostat housing. Unfortunately this is a solid bolt, so you'll have to remove it to let the trapped air out.
( I drilled about a 3/32 axial hole down the center of my bolt, and about 1/4 of the length down from the cap I drilled a radial hole in one side & that picks up the axial hole. Someone said that one of the P* models has a pre-drilled bleed bolt that droops right in.)
If you don't have a drilled bolt, the air will come out in a hurry, followed by a pencil sized fountain of water.( You'll want a BIG wad of towels in place for this!) Now put the bolt back in & clean up the mess. (Don't rush too much & drop the bolt tho!)
5) Repeat steps 3 & 4 until you don't get any more air out. It's best to wait 10-15 mins between each round of steps, but not mandatory.
6)Fill the coolant tank to within 6cm(~ 2") of the top & cap it.
Take a drive!
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stu cordova (Balataboy)
Member
Username: Balataboy
Post Number: 472
Registered: 4-2001
| | Posted on Monday, July 21, 2003 - 10:10 am: | |
Stevo - an '85QV since new? WOW - that very impressive!! Cheers |
Jeremy Lawrence (F512m)
Junior Member
Username: F512m
Post Number: 155
Registered: 1-2002
| | Posted on Monday, July 21, 2003 - 9:28 am: | |
Steve,
Your problem sounds just like mine. I haven't checked the thermostat, but I have to bleed air out of the radiator every few days. When I crack the bleed screw, I get about 10 seconds of air before I get any coolant.
Well, I have to take her in to JRV to have the exhaust leak fixed. I will have him look at that also.
Is there an aftermarket thermostat for the QV?
JL |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 715
Registered: 4-2002
| | Posted on Monday, July 21, 2003 - 5:56 am: | |
Coolant can exit the cap through the overflow/vent hose. If the pressure rises sufficiently, the spring loaded cap opens and coolant goes out the hose that is attached to the neck of the reservoir.
Does your car have a vapor release (bleed) on the passenger side of the radiator? If so, release some of the vapor/gas. Others have another bleed bolt in the thermostat area.
What I say applies to a 328 but they are probably very similar. |
Ming Cheng (Onlinesys)
Member
Username: Onlinesys
Post Number: 314
Registered: 5-2002
| | Posted on Monday, July 21, 2003 - 5:20 am: | |
Don -- I encounterd a bit hot on my 456 as well and the dealer reckoned it should be normal for 456 or 550 under the ambient temp at 32-33 degree C.
Dave -- How could the coolant be splited out if the radiator cap is closed securely? also, how could the over-filled coolant affect the temp?
Thank you!
Stu -- Mine is fine on freeway driving and is below the 195 mark but it could be at 210 in Stop/go traffic.
Cheers |
Steve Henderson (Stevo)
New member
Username: Stevo
Post Number: 3
Registered: 6-2003
| | Posted on Monday, July 21, 2003 - 3:38 am: | |
I have an 85QV from new.In the eighteen years I have twice had problems with overheating.The first episode was difficult to diagnose but was eventually found to be due to the thermostat opening at a higher temperature than specified but going on to open fully.It appeared that this situation did allow vapour to develop in the heads which went on to displace coolant which was discharged from the expansion tank but only in the warm up phase.However this unnoticed episodic loss of coolant eventually leads to a situation where there is recognisable overheating.A new thermostat fixed the problem. Then eight years later the same ocurred and a test of the thermostat revealed delayed opening again. Fixed once more with a new one. Thus I would suggest that at least the thermostat is checked for opening at the right temp and that it opens fully. I don't have the manual to hand but if the specs are not supplied by another member I will post them shortly. Stevo |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1353
Registered: 5-2001
| | Posted on Monday, July 21, 2003 - 2:26 am: | |
Don't overfill the expansion tank either, it is supposed to be no more than 6cm from the filler neck, and some cars prefer a bit lower, or they will spit (burp)out the excess |
stu cordova (Balataboy)
Member
Username: Balataboy
Post Number: 471
Registered: 4-2001
| | Posted on Monday, July 21, 2003 - 1:17 am: | |
Not unusual considering time of year. Check for obvious - coolant level, fans switch on and off as designed, radiator cap in good condition.
One way to check if all is well is to get it out on the highway. Mine will be same as yours in the city, but as soon as I hit the freeway, cruising at 70+, she cools down in a hurry. I love freeway driving and so does the car! |
Don McCormick (Dandy_don)
Junior Member
Username: Dandy_don
Post Number: 83
Registered: 2-2002
| | Posted on Monday, July 21, 2003 - 12:16 am: | |
If it is as hot outside where you are as it is here in Kansas City then it sounds fine to me. If it doesn't overheat then I would leave it alone. Don |
Jeremy Lawrence (F512m)
Junior Member
Username: F512m
Post Number: 154
Registered: 1-2002
| | Posted on Sunday, July 20, 2003 - 11:28 pm: | |
85 QV running at the mark past the 195 mark. Doesn't get hotter than that, but hotter than normal. What should I check?
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