Pushing coolant, no exhaust gas in thermostat housing.

[Bojangles465]

My 90 laser rs-t fwd has been pushing coolant, and for shits and giggles, I rented a block tester, the fluid doesn't change color, so that means there isn't any exhaust gas in the coolant. I replaced the thermostat and the radiator cap, along with the radiator, so idk wtf is going on with it. Please help... I bought arps and a cosmetic mls hg, because I thought it had to be the gasket, but apparently not...:/

 

[Dhan]

Have you done a compression test on all four cylinders? If so, what are the results?

If you recently flushed the coolant system, you could be still getting air pockets out.

It might be a slow leak, like out of the heater core hoses behind the intake manifold or something. There aren't many places coolant can escape from that aren't noticeable.

Can you 100% verify that you aren't burning it? It would be white smoke out of the exhaust.

Before buying anymore parts, narrow down the problem.

 

[-red97rum-]

How much boost are you running with that 16g? It could still very well be a head gasket issue, but doesn't show up until the engine is under a heavy load.

 

[Lou98GSX]

the best way to check for a bad head gasket is a leak down test . with air pressure in the cylinder you will see the antifreeze slowly rise .

 

[Bojangles465]

Have you done a compression test on all four cylinders? If so, what are the results?

If you recently flushed the coolant system, you could be still getting air pockets out.

It might be a slow leak, like out of the heater core hoses behind the intake manifold or something. There aren't many places coolant can escape from that aren't noticeable.

Can you 100% verify that you aren't burning it? It would be white smoke out of the exhaust.

Before buying anymore parts, narrow down the problem.

Cylinder 1- 120 psi
Cylinder 2-120 psi
Cylinder 3-122 psi
Cylinder 4-125 psi

I'm not getting any smoke from the exhaust, black, white, blue, grey, or any variation of the above. Cooling system is holding pressure, and I've burpe the system 30 times.

How much boost are you running with that 16g? It could still very well be a head gasket issue, but doesn't show up until the engine is under a heavy load.

1 bar , right above 7 lbs on the stock boost gauge.

 

[Dhan]

1 bar , right above 7 lbs on the stock boost gauge.

The stock boost gauge isn't really reliable FYI. Compare it to an aftermarket gauge and you'll agree. But if you're just on the stock system and running standard factory boost (~10psi), it shouldn't matter.

A hot or cold compression test is an easy first step that shows that you can make consistent pressure. If you did everything correctly, and those are your numbers, I would move on to a leak down test (as stated above).

A leak down test will see if the car can hold pressure.


I should have asked this before, but does the car actually overheat? Or are you just noticing that the coolant isn't always topped off?

 

[Bojangles465]

The stock boost gauge isn't really reliable FYI. Compare it to an aftermarket gauge and you'll agree. But if you're just on the stock system and running standard factory boost (~10psi), it shouldn't matter.

A hot or cold compression test is an easy first step that shows that you can make consistent pressure. If you did everything correctly, and those are your numbers, I would move on to a leak down test (as stated above).

A leak down test will see if the car can hold pressure.


I should have asked this before, but does the car actually overheat? Or are you just noticing that the coolant isn't always topped off?

My temperature gauge doesn't work, so I can't be certain, but I do have steam and a bubbling noise coming from the over flow. When I remove the cap of the over flow, there is steam and air blowing into the water, which is what causes the bubbling noise. This only happens once I drive, and the overflow fills up and spews water from the bottom overflow hose leading to the ground. Ps, it is running stock head bolts torqued to 65-70ish, with a composite OE head gasket.

 

[northernawd]

sounds like a headgasket. im currently doing a headgasket on my DD. if you overheat it enough your going to cause some serious damage to your motor

 

[Bojangles465]

Update: those compression numbers are wrong, those are old numbers, I got 150 straight across the board, and I let each cylinder hold pressure for 10 mins and none if them are leaking... What now?

 

[kchaazz]

So, after reading the above post, am I to assume that you did a leak down test, that the pressure held for ten minutes, and during the leak down test, the coolant level did not rise at all when you took the rad cap off the thermostat housing during the test?
Since your temp gauge is inoperable, Ive got two questions for you. Is your passenger side radiator fan working? If so, is it the stock fan, or? Reason I ask is, if you are overheating for any reason, youre going to lose coolant out the overflow. When the coolant expands under normal temps, some coolant is expelled into the overflow, and when the coolant cools off, it contracts and whatever coolant was sent to the overflow is then supposed to be pulled back into the system. In the case of overheating, the coolant expands and boils to the point that it will fill the overflow bottle and piss out the overflow tube, resulting in your coolant loss issue. This is of course ASSuming that you have properly verified that the loss isnt occuring through the headgasket.

 

[SICK SOCIETY DSM90]

I would have to lean towards a head gasket leak somewhere or a bad water pump would cause it to over heat. one quick way to know if your head gasket is leaking check the dipstick coolant and oil don't mix you should see it being watery or smell not like regular oil. not always full proof but its free and only takes a few seconds. either way your coolant is going somewhere or is not being circulated enough to cool the car down. keep us updated on what you have tried and if its been fixed.

 

[Bojangles465]

So, after reading the above post, am I to assume that you did a leak down test, that the pressure held for ten minutes, and during the leak down test, the coolant level did not rise at all when you took the rad cap off the thermostat housing during the test?
Since your temp gauge is inoperable, Ive got two questions for you. Is your passenger side radiator fan working? If so, is it the stock fan, or? Reason I ask is, if you are overheating for any reason, youre going to lose coolant out the overflow. When the coolant expands under normal temps, some coolant is expelled into the overflow, and when the coolant cools off, it contracts and whatever coolant was sent to the overflow is then supposed to be pulled back into the system. In the case of overheating, the coolant expands and boils to the point that it will fill the overflow bottle and piss out the overflow tube, resulting in your coolant loss issue. This is of course ASSuming that you have properly verified that the loss isnt occuring through the headgasket.

Yes, I did the leakdown test with the radiator cap off, and the coolant did not rise. The coolant only spews out if the overflow hose if it is driven, it can idle and it won't push the coolant. I have an eBay j pipe that won't allow me to use the fan in the stok location so I have it in between the bumper and the radiator, blowing air towards the bumper. I am running straight water right now btw. Also, the water pump is circulating, I can see the water moving in the thermostat housing.

 

[dacowgod]

If you have stretched the head studs/bolts you can "lift" the head and it will only push coolant during load... it wont show up on a leak down or a compression test...

also if you get the car hot enough to boil the coolant it can push it...(Boiling point varies depending on pressure of cap, amount of water vs coolant etc)

Also if your radiator cap is faulty it can push coolant......

 

[SICK SOCIETY DSM90]

I agree about the faulty radiator cap could cause problems with pressures and boiling just sounds like something more worth a try its a cheap part. Even if you can see circulation is it pushing enough water in your case which is okay for testing but really need some coolant in there. From a personal experience I had an older Honda that over heated not right away but under driving conditions and it was a water pump still circulating just not well enough when I compared the old to the new it was a very slight but noticeable difference in how free it spun. it could only be a few things the system is very simple compared to newer cars.

 

[KT_McHan]

I have an eBay j pipe that won't allow me to use the fan in the stok location so I have it in between the bumper and the radiator, blowing air towards the bumper.

If I'm reading that correctly, that could be a big part of the problem.

 

[CrashGNX]

Yes, I did the leakdown test with the radiator cap off, and the coolant did not rise. The coolant only spews out if the overflow hose if it is driven, it can idle and it won't push the coolant. I have an eBay j pipe that won't allow me to use the fan in the stok location so I have it in between the bumper and the radiator, blowing air towards the bumper. I am running straight water right now btw. Also, the water pump is circulating, I can see the water moving in the thermostat housing.

Yup, thats most likely your problem, air needs to be blown from the radiator tward the engine, Most times aftermarket fans just dont move enough air even when pulling through the radiator in the correct direction. I think STM sells a shrouded Flex-A-Lite fan that moves enough air to replace the stock one and should clear your J-pipe.

 

[kchaazz]

The fan is absolutely the problem, and running whatever fan youre running in the configuration youre running it in with no temp gauge isnt a good idea. Why is the temp gauge inoperable? Bad sensor in the thermostat housing? Spade plug broken off the wire to the sensor? Id fix that ASAP, and get the factory radiator fan back in there, or you need a high quality aftermarket unit- FAL and SPAL are the only two companies Ive ever seen to make good fans. Stop driving the car until youve corrected this or you will be in for a lot more work and out a lot more money.

 

[SICK SOCIETY DSM90]

Ya i would have to agree with defently need good air flow or you will never keep it cool regardless how everything else is working. I would get the teyoump gauge fixed before you are driving overheat everything and cost yourself alot of money .

 

[-red97rum-]

If you have stretched the head studs/bolts you can "lift" the head and it will only push coolant during load... it wont show up on a leak down or a compression test...

This is what I was getting at, it's a very common occurrence.

 

[SICK SOCIETY DSM90]

Ya from the very short time owning a talon dsm these cars love to breath and do not like restrictions at all especially the turbo dsms.

 

[counti41]

have yo done any elimination of your heater hosed check your routing of your coolant lines make sure you are not running a line from your hot side to your cold side before your radiator, that would cause you to over heat. don loop any lines cap hem off

 

[Bojangles465]

Wait, so the fan should be blowing the air through the radiator towards the engine? I know this fan I good enough, considering it's a jeep grand Cherokee fan( previous owner did this, this bloods not on my hands! )

 

[SICK SOCIETY DSM90]

Ya you have two fans on the radiator originally ones a sucker fan and the other is a pull fan. meaning one fan sucks air into the radiator and the other blows towards the block when hot. if your blowing away from radiator its cooling the air not the radiator easy fix most fans you can switch the wires and it will operate as either some don't just got to play with it some.

 

[Dhan]

Ya you have two fans on the radiator originally ones a sucker fan and the other is a pull fan. meaning one fan sucks air into the radiator and the other blows towards the block when hot.

They both pull air. The driver's side fan will kick on to operate the a/c. The passenger's side fan is for keeping coolant temps below 210* when at idle. If the temps rise enough, they both kick on.

OP, you need to fix that temperature gauge. Seriously amigo, that's like a $10 fix that could help avoid a $1000 fix.

If possible, stick to the OEM cooling system, this includes the radiator and fan(s). It's actually pretty efficient.

 

[SICK SOCIETY DSM90]

either way the fans need to go back to the original spots if possible. that most likely will fix your heating problem. i agree with the post above you can spend 10 dollars and get some fans from the salvage yard or new watever one you like best and save yourself a new motor