rsabeebe

i've been having coolant issues since i picked up my 951 and now they have developed to being even more problematic. curious if anyone here would have thoughts on areas to attack first - this is my first 951. initially, the car would 'puke' coolant after certain commuting trips to work and back. i have twice lifted the front end and used to gravity method to top off and bleed the system. interestingly, when i do fully top off the system, i get a few minutes of steam coming from the exhaust side of the motor and i'm concerned that might be a head gasket going. after my commute home last might - just 8 miles - it puked coolant again in the garage and i'm thinking the coolant system is possibly being pressurized from the [potential] head gasket leak and pushing the coolant out of the overflow. i have swapped the reservoir cap and i have other parts to replace, but it's been too damn cold here lately. on top of this, the interior has erratic heating of late - at idle there is no heat, rev the car and i would get heat. as of this morning, even at full driving operating temperature, i had no heat in the car. i plan to change out all of the coolant hoses, the thermostat and sensors, but could this also be the heater control valve? also, what are people's impressions of the potential head gasket issues? any thoughts on this whole lousy issue would be appreciated. thanks!!

Mangonesailor

Heater issue sounds like you're low on coolant... which you've seemed to have figured out.

Steam from the head side? Have you checked the hose coming off of the head-mounted tube located above the header? Are your hoses in good shape? If so, might want to try a leak-down test.

rsabeebe

i have not checked that hose connection - thanks! i will check that connection tonight. i have all new hoses on order to simply replace all the hoses that appear to be original. i've only had the car less than 1000 miles and i seem to be having issue after issue with the car. welcome to 951 ownership.

bordin34

If you are stuck at a light does the temperature gauge creep up? If you rev the engine to about 2000rpm does it drop? This is the case when coolant gets too low.
From what you said it sounds like a head gasket issue to me unless you find a visible leak.
Also check your oil to make sure it isnt a milkshake.

Van

I'd replace the expansion tank cap... Usually a head gasket will break between the water jacket and the cylinder bore - which won't have coolant in the oil and won't make steam in the engine compartment, but rather will make steam/smoke in the exhaust.

If the head gasket leak is small, you might not see steam in the exhaust, but it will, as you suspect, pressurize the coolant system and push fluid out.

rsabeebe

that hose connection seems fine. will need to look a bit better when i have a chance. what i have noticed is that when it does steam, the header flange towards the rear gets wet right below the cam cover. getting fed up with the difficulties i'm having with this car and i've only owned it a little over a month.

rsabeebe

absolutely correct. under normal driving conditions, the needle is down around the bottom mark. at a light or in heavy traffic, the needle will rise to or above the 3rd (top) mark, at which point the fan(s) kick in. as you mentioned, if i rev the engine, the temps will drop back down. added more coolant this morning and got heat back in the car. need to drain the oil and check condition of that, but i am def losing coolant somewhere, somehow.

rsabeebe

expansion tank cap is brand new as of last week. i also have other items to change, as a precautionary measure, but i haven't gotten to them due to the ridiculously cold temps lately in TX.

since i just bought the car from a well known (on RL), local dealer a little over a month ago, i'm quite disappointed that i'm having such issues and potentially an issue with the head gasket this recently after purchase. i haven't even mentioned the other things going wrong with the car.

rsabeebe

i'm wondering if someone can tell me why the following could be happening... obviously, something is majorly amiss in my cooling system. with a refill of coolant, i once again have heat, but it depends on how the car is running to determine what i get. if i'm driving along at normal road speed, i get plenty of heat and actually roasted. now, at the same exact heat setting and fan speed, i lose virtually all heat at slow speeds and a standstill. at red lights, i lose all heat and it blows cold. what is up with that?? would appreciate any thoughts.

travisgreen

Seems to me your system is not bleed properly and you have air in the system not allowing you to get enough coolant in

travisgreen

Are you using the bleed screw at the thermostat?

Donaldx3

I'm with the one that said head gasket. If its spitting it out when you park and you look at your reservoir tank and it looks filled past the max then it's head gasket. Had this same problem about 4/5 years ago normal driving all good came to a light that needle shot up or check your radiator to see if it's good cheaper fix then head of its not that check pump and thermo if not that then most definitely your head and also check the oil if it comes out like a milk shake then its your head

travisgreen

I only read the very last post I didn't scroll up, sounds like something other than air with tps issues but if it's burning or leaking it you should be able to pin point it, Check the plugs, oil, exhaust

Van

For your heat, the valve to the heater core is controlled by vacuum. If you have a bad check valve in the system, you'll get times when you have vacuum (throttle body shut, coasting down hills) and times with the throttle body open, and perhaps making boost...

There is a "vacuum reservoir" over by the battery that supplies the vacuum for the HVAC when the car is on boost. I've seen the nipples on these reservoirs crack, too.

bordin34

Interesting. I would think that the engine should pull more vacuum under idle than while cruising.
Check out my thread from last year when my head gasket went. Also I didnt resurface the head and think it is going again, about 2000 miles later.
http://dorkiphus.net/porsche/showthread.php?t=29499