1998 Coolant System Breather

[nubuilder]

I just drained, flushed, and refilled my coolant. Then the water pump went a week later. So drained, replaced, filled again.

 

I think there is a lot of air trapped in the system.

 

Does anyone know if there is a breather hose/vent somewhere easy to get at?

 

There is a small, 1/4 inch hose that has a plastic plug in it that is clipped to the back side of the fan shroud on the driver's side.

Is this it?

 

Thanks.

[matt76]

im not positive but i think that breather tube u see up front is for the front diff, there is another one on the fire wall which i think is for the trans.

there isn't any breather type hose for the water pump. there is that weep hole, but im not sure what thats for.

 

you should be able to get all the air out of the line by removing the cap, start and run the engine and squeeze the upper and lower hoses until u don't have any more bubbles coming out.

i doubt your fluid change had anything to do with the pump failing.

[nubuilder]

The only thing I can think of is that when I flushed the system, contaminants & rust broke loose from inside the pump/entire system causing the seals inside of it to leak.

Coolant was coming out of the weep hole.

The weep hole is there so that if liquid freezes inside the pump, the pump won't stop the serpentine belt and burn it up (I think).

 

I looked closer at the tube I saw on the fan shroud and it either goes to the front diff. or the power steering pump.

 

I've read about the "take the cap off and run it" thing in a few places. I just hope fluid doesn't spray out.

 

I'll give it a try.

 

Thanks

 

PS - I wrote up a thread on draining the radiator and installing a Volant CAI if you are interested in either of them since you have a '98

[nubuilder]

UPDATE

 

I parked my truck on my driveway for 2 nights (not back to back) with the cap off. I don't know if the fluid level actually went down on its own or it went down because of me taking the cap off when warm and coolant bubbling into the overflow tank (nothing spewed out of the system though). I also let the truck run for about 15 minutes while on the driveway (or however long it took to get the T-stat to open).

 

I haven't checked it in the last 3 days, but I will this weekend. I'm hoping for a full radiator and the over-flow tank to be at or below the COLD mark.

 

I'm still having a problem of running way to cold. The T-stat opens at 180 but goes down below the 155 mark (next big white mark). It never gets higher than about 165-170 (suppose to maintain 180).

The truck is blowing HOT air (as hot as it was before the flush).

 

This may be unrelated to the coolant flush, but I think the cold operating temperature is affecting it.

I have put a can of Seafoam in my tank before filling it up. I hope it is cleaning off the sending unit for the gas gauge because I'm down to 3/8 of a tank with 200 miles (usually hit 1/2 at 200 miles). I highly doubt my intake gasket it gone (or coolant getting in the cylinders) since the truck is running fine. All I can think is that the Seafoam is breaking loose a lot of deposits in the fuel lines and injectors causing more fuel to flow/be used. We'll see what my mileage actually is when I fill up next week.

[nubuilder]

I filled up today. 13.37 MPG. 0.4 MPG worse than last tank (which Hypertech said my MPG would only go down 0.5 if the engine was running cold & rich, huh maybe the T-stat is bad). A year ago at this time I was getting very slightly higher, 13.9. Looking back at my records, the end of Feb/beginning of March is when they must have changed back to summer blend because my MPG went up DRASTICALLY. A jump from 11.7 to 14.9.

 

I also called Hypertech (I bought their 180 degree). The call lasted 15 min and I was on hold for at least half the time. The guy said nothing is wrong with the T-stat (of course he would). He said that (loosely quoted) "your truck is not programmed to function with that particular T-stat. In the '99+ trucks, the temp gauge is actually an idiot gauge. Manufacturers were getting so many complaints about vehicles running too cold that they got away from real gauges. The new trucks are all set to go half way up the temp gauge and stay there. The only thing they do otherwise is if the engine is over heating, the gauge will peg out quickly." WTF??? I don't know about anyone else, but MY gauge is a real gauge. It fluctuates. However, what he said does make sense looking at my parents' newer vehicles. The gauges just seem to sit there and never move. Even when the T-stat does open up.

 

Anyway, this phone call got me no where. I stopped by AutoZone to see if their scan tool could read my engine temp. Theirs could not. I'll have to try AdvanceAuto or Oreilly's next. I knew they would blame the gauge. It's the easiest thing for them to do. So I plan on putting my old one back in (it was very clean when I removed it; only changed it because I was changing the coolant anyways) and see what the truck does. If it warms up and maintains <200, I know the Hypertech one is junk. Then I'll get my gauge checked by one of the local stores and see if it is indicating the proper temperature. If it is, then I can tell Hypertech that the T-stat is bad.

 

I'll never mail-order a T-stat again!

 

Wish me luck!

[nubuilder]

Sorry to bring this back, but I have my last update.

 

I am now officially never buying HyperTech anything ever again. The truck is still running 140-160 when the T-stat opens up. When it does open, the temp drops from 190 to 140 very suddenly. I know that this is definitely affecting my MPGs now.

 

I tried to remove the T-stat housing without draining any coolant. This does NOT work. I tried to squeeze the coolant from the upper hose to the radiator. I just squeezed it so it would leak back into the overflow tank. I thought I got enough out, but I guess not. Coolant leaks out all over the place.

 

When I change the T-stat, I plan on squeezing the upper hose again. I'm going to disconnect the upper hose from the radiator and use a siphoning thing (looks like a fuel primer on an outboard boat) to get out the rest that is still siting on top of the T-stat.

 

The moral of this story is: STICK WITH STOCK!!!!!!

 

The only way you should/could go with a 180 or 160 T-stat is if you are somewhere hot or have you PCM reprogrammed.

[mcreyaufmiller]

You can also compare the temp to the gauge by taking the temp of the radaitor when warm. They should match, I know in mine the temp gauge shows the truck to be running cold, but it is at the correct temp according to the actual temp.

[kuhl_530]

When it does open, the temp drops from 190 to 140 very suddenly.

 

Mine does the same thing, and it's all stock. My water pump actually took a crap on me last week, so while I was replacing it I also did hoses and thermostat, thinking that it was bad. Nope... still does it. When I start it up and drive to work, it goes from cold up to 210, then suddenly drops back down to about 150, then up to 185 or so. The old one used to bounce back and forth between 210 and 150, but the new one seems to hug 185 pretty close. I'll have to keep my eye on it, though.

[nubuilder]

That's just the thing. The old one never dropped like this. However, the pump may have been leaking before all this and the fluid level was so low that the truck would run a little hotter than it is supposed to. So when the T-stat opened up finally, the coolant may have been really hot to start with and cause the temp gauge not to drop (use to only go down to about 185-ish). I really wish there was a way to see what the ECM thought the temp was. I just want to know if this is affecting my MPGs / fuel mixture. It's really hard to tell right now because they switched back to summer blend this time of year last year.

 

Did you have fun getting the fan off!?!? I ended up buying the removal tool (took it back 1 hour later). It works, but I don't like how it can ruin the heads on the bolts holding the pulley on the pump.

[OldCrLvr]

The weep hole is on the outer side of the bearing for the shaft. When the bearing and or seal starts to go it will leak past it and drip out the weep hole.

I don't know about your truck but in the mid to late 90's the Camaro had a air bleed on the intake.