Not pulling coolant back in, need serious help from the big boys.

[surgeon_general]

Ok some members have had similar problems but I'll give you the stats on my car.
93 tsi with a 6 bolt swap, the fiav valve and iac motor is blocked, i blocked my heater core off to eliminate it and my problem is the same.

I push coolant out, i dont suck it back it.

I pressure tested the coolant system numerous times and it holds pressure for 24 hours and longer. New radiator cap. I retourqed my head studsdown and the exhaust side of the driver side was a hair loose. I drove the car a couple times after that and did a compression test my numbers for 1,2,3 and 4, respectively are 172, 165, 175, 170.

Given that i swear its not my headgasket, but I dont know anymore. my waterpump weep holes look perfectly dry. so i need some help. throw ideas out there for me to check.

thanks so much, steve

 

[95blackGsTurbo]

Did you try the simple things like pulling your upper and lower hose off and checking for blockage as well as all of your other lines. Did you check your thermostat to make sure it's opening up and allowing coolant to flow? If it doesn't open it can't flow anything.

 

[drewvr4]

headgasket

and before everyone freaks out and says there isnt a mix of coolant and oil there doesnt have to be for there to be enough combustion getting out to slowly push out the coolant.

run the car when its warmed up so the thermostat is open, does it shoot coolant out?

if not the only want to eliminate if its a headgasket is to go to a shop and have them run a test where they take a sample of coolant and if it turns yellow you have exhaust gasses in your coolant.

ive had this exact problem happen twice.

 

[surgeon_general]

I have a new thermostat and everything as well.

what kind of shop does that test? the shops around here are pretty lame to say the least my usual local shop has not even heard of that just to give you an idea.

thanks for the replies as well.its pissing me off to say the least, the car runs so good right now.

 

[95blackGsTurbo]

Does the car overheat? Or are you just worried about it pushing coolant out? Does it do it only when it's warm or when it's warm and cold. How much coolant did you put in it? Should put the cap on and let it run for a while.

 

[surgeon_general]

the car does not overheat, i check my temps on the logger and im staying around 200F all the time, it pushes the coolant out then does not suck it back in so my coolant is low by however much it fills the coolant bottle up. I have to empty the overflow bottle back into the system manually every time instead of it pulling it back in by itself.

 

[TjPhillips36]

Sounds like you have either...
1. A Faulty Thermostat
2. Installed the thermostat backwards
3. Have a headgasket failure
4. Have Something in your coolant lines blocking flow

 

[95blackGsTurbo]

Definately sounds like a backwards thermostat. I have seen it done a couple time's but not very often. Also check your cap. That is what regulates the coolant being pulled back in. If the spring or seal is bad it will push coolant back in all the time.

 

[drewvr4]

i dont know what kind of shop would do it, i hadnt even heard of it until my buddies shop had the SnapOn guy there and overheard us and sold it to the dude, it cant cost much.

 

[snox135]

How did you block off the heater core? I'm not sure how the coolant lines are routed on a DSM. But I know a lot of cars have the return line going back to the radiator. This allows the water pump to be moving coolant when the t-stat is closed. So maybe if it is blocked off and not routed together this is causing the issue.

 

[surgeon_general]

the thermostat is not in backwards, when it doesnt pull the coolant back in, i can look at it.

i bypassed the heater core by taking a piece of copper tube and connecting the lines from the heater core together so the coolant can flow through like normal

I was considering the flow problem but I dont see what really could be blocking it since it doesnt overheat and i replaced the radiator and stuff.

im thinking more and more headgasket seepin some pressure in. sigh.

 

[Defiant]

Air leak in the siphon return line.

 

[Talesin]

Agreed, replace the hose going down into the overflow tank, and the one from the thermostat housing to the overflow tank. Make sure the fittings in the cap aren't cracked. Er, and just to state the obvious, make sure your overflow tank is half-full and the siphon tube is submerged in it. And if you haven't replaced your radiator cap recently, they're cheap, and worth a shot.

Easy way to see if the headgasket (or the head core itself!) is the problem in this case is to let the car cool completely, take off the radiator cap, and have someone watch while you start the car. If it shoots water up, you have a leak (somewhere) from one of the pistons into the coolant system. If it's running right, you should be able to start the car with the cap off and let it idle for about half a minute before it starts to heat up enough to displace and start overflowing out the thermo housing.
Was what happened with mine twice. Once due to a failing head gasket, the second due to a manufacturing defect in the head itself.. coolant finally ate through and started leaking out through the #1 exhaust runner. Drove me nuts as it didn't leak enough to make smoke, but I kept losing water.