cant hold a steady temp

[95awdboost]

So recently I've had some trouble maintaining temps so I found what I though was the problem and replaced my lower radiator hose that had a tiny tiny hole and though would help but it didn't, whenever I'm driving and I get anywhere between -10 vac and about 0 the temp starts rising gradually but if under -10 then temps are fine....any ideas ?

 

[1990AWD]

That's not very much info to go on. Is this just when cruising in the city, or highway and some hills? Does it overheat after a hard run in boost?

Some things to check.

Full and clean coolant 50/50 mix.
No air blockages
Rad isn't plugged
Fans are working.

 

[92AWDHX40]

Could be several things, gotta pick one and see if that fixes the problem. thermostat, hg, leaks, and so on.

 

[95awdboost]

Its usually only on hill on the highway but sometimes on flat ground but always above -10 vac......I haven't really boosted that much cause I'm not wanting to cause anymore issues but the rad was jus flushed n fresh coolant put in and vans are hooked up and workin

I've changed the thermostat like 3 times had a 180 t-stat then a 170 and now a 160 and no help at all

 

[1990AWD]

What's your compression? Are you burning coolant? As said, if your headgasket is leaking or even if your compression is low it can cause overheating.

 

[92AWDHX40]

We cant guess, do a compression test.

 

[95awdboost]

Yes I'm burning coolant and I don't know what my compression is...would it be safe to say my head gasket could be the culprit?

 

[1990AWD]

If your burning coolant and overheating, isn't that a little obvious?

 

[92AWDHX40]

Again start somewhere then we can go from there.

 

[95awdboost]

Well I had a hole in a hose so I figured that's what was causing my coolant. To be disappearing but I'm at work now so there is little I can do.....I guess tomarrow ill pull the head and see what the gasket looks like

 

[92AWDHX40]

Before you do that do a compression test, could be a simple fix.

 

[95awdboost]

So say I do a compression test and its good what would be my next step ? N if its bad rip off the gasket right ?

 

[MY1GDSM]

A leak-down test will tell you a lot more then a Compression test... Just a thought to keep in mind.

 

[eli96talon]

+1 on the headgasket.I had the same issue as you are having it turned out it was the headgasket.one way to tell is take the radiator cap off and turn the car on once its to temp look inside the water neck where the water flows.if you see foaming or rapid bobbles inside the water neck it means the headgasket is leaking into your cooling system.it will cause strange over heating issues.

 

[98_gsx_]

try changing your thermostat

 

[MY1GDSM]

try changing your thermostat

Read the thread the whole thread before posting The OP stated that they have changed it three times

 

[95awdboost]

So I did a compression test today and its was 150 in all four cylinders

 

[ssjkouru]

I had a problem with overheating as well and it turned out to be my radiator fan wasn't working. after you run your car for a while, park then get out and check to see if the fan is running while the car is on.

 

[Tiki2777]

Did you replace all the coolant that most likely you lost through that tiny hole? I got really wierd and all over the place readings when i ran with like 3.5-4.5 quarts of coolant (i know, really bad, i didn't know). Make sure thats in check.

 

[95awdboost]

The radiator fans work fine and yes I've replaced the coolant

 

[tfaulk21]

Check your waterpump pulley see if it has play in it. If it does than its going bad and your belt will fall off in the future and it sucks. Mine acted the same way it was like an old woman and hot flashes it would be fine one day that. Want to overheat the next

 

[mb3000]

What condition is the radiator in, do you have a fmic?

 

[1990AWD]

You said you were burning coolant so I'm still thinking headgasket. Your probably pushing coolant as soon as you get even close to being in boost but not at an idle since cylinder pressures are a lot less.

 

[95awdboost]

radiator is in good condition and no fmic... the cars at the shop now having the coolant system pressure tested but i've been thinking its prob the head gasket but when i get it back hopefully this afternoon ill know the culprit