Hi All
Hope you can help with a strange heater issue I am having. I was getting the MR2 ready for MOT after not having driven it for about 3 months and I noticed the heater was only blowing lukeware even though the car was up to temperature. My first thought was an airlock in the radiator or heating matrix (again!) but intake/outake pipes into both are nice and toasty. Bled the system anyway which didn't help.
I noticed that even tough lukewarm air is coming out of the windscreen vents, centre console vents and footwell - for some reason the two side vents at each side of the dashboard are blowing hot as a furnace!
It's not a major issue for me as the inside of the car does heat up eventually but it takes a while to demist the windscreen at that temperature.
Any ideas would be appreciated.
Sounds a bit like an air lock.
Bleeding the coolant should do the trick. Unfortunately it's a bit of a convoluted exercise but it's not difficult.
Check the how-to section for how to replace the radiator, that has it in there. Actually there might be one one on bleeding the coolant system.
It involves removing the plastics from the frunk (a few push pins, easily done) and using the plastic tubes that should be rolled up against your front bulkhead on one of the bleed valves.
I've had something similar for a some time. I'm satisfied that it's not a simple airlock.
My central dash vents are a bit on the lukewarm side, while the side vents are hot as.
I've flushed the heater matrix and done everything to ensure it's not an airlock.
I think it's loss of control of some flaps that control the air movement.
As this means a major dismantling of the dash, and as the cab still gets plenty hot, I've decided to leave it for now.
I've not seen a heater unit out of the car and I'm not sure just how it's arranged, but I notice that the left-hand central dash vent has very little air flow, while its buddy has more. Something is messing with the flow of air.
All the vents work evenly when using the A/C.
One of these days, I'll spend some time at Rutland MR2 and tear into one of Dean's scrappers....
Hi Shnazzle!
I've already tried bleeding the coolant system and it didn't make a difference.
The radiator cracked at the end of 2017 and I replaced it with a cheapy from ebay, flushed the system and replaced with geniune red coolant. I had an airlock at that point which was a bugger to get rid of (had to clamp one of the hoses and suck coolant through with a big syringe). I seem to remember at the time all the vents were blowing cold.
I can't understand why the side vents would be hot while the rest are not?
Quote from: Carolyn on January 28, 2019, 17:27
I've had something similar for a some time. I'm satisfied that it's not a simple airlock.
My central dash vents are a bit on the lukewarm side, while the side vents are hot as.
I've flushed the heater matrix and done everything to ensure it's not an airlock.
I think it's loss of control of some flaps that control the air movement.
As this means a major dismantling of the dash, and as the cab still gets plenty hot, I've decided to leave it for now.
I've not seen a heater unit out of the car and I'm not sure just how it's arranged, but I notice that the left-hand central dash vent has very little air flow, while its buddy has more. Something is messing with the flow of air.
All the vents work evenly when using the A/C.
One of these days, I'll spend some time at Rutland MR2 and tear into one of Dean's scrappers....
I suspect you are correct about it being some kind of air direction issue. It doesn't bother me enough to tear out the dash and find out though :-)