thermostat or water pump

[ricoman]

I have a 95 4runner with the v6 engine. I noticed coolant leaking in my driveway. I assumed it was the water pump but when I look at the manual, it look like it's coming from higher up where the thermostat is (the housing where the hose hooks up). The temperature guage hasn't really changed. Can I assume it's the thermostat? I'm just mediocre mechanical-wise so trouble shooting isn't my strong point and I don't want to start "fixing" things that aren't broke. Does changing the thermostat and putting in a new gasket sound like the right place to start? Or are there other things to check as well?
Thanks.

 

[blaniac22]

Typically, when I replace a water pump, I'll throw a new thermostat and gasket in anyway because I've already drained the coolant and it's easier to do so at that point.

So, if it looks like it's coming from there, I'd change it first and it's really nothing lost if it doesn't fix the problem. Make sure you check all the hoses and clamps. It may be blowing back from somewhere or running from a hose.

Honestly, I've never worked on that engine, so I'm not really familiar with it. I've changed out pumps, hoses and thermostats on other vehicles though. So, my advice is pretty generic. I'm sure someone will come along soon that can help more - but that's just my 2 cents.

 

[ricoman]

I've been looking at online parts for a thermostat. There seems to be several for the 3ve engine from 180 degrees to 195. How do I tell which one I need. I live in CT and winters are pretty bad here it that make a difference.

 

[hoe_nah]

how many miles does your truck have?
if its time to do a timing belt you should just tackle everything all one time

 

[ricoman]

how many miles does your truck have?
if its time to do a timing belt you should just tackle everything all one time

I've only had the truck for about 3 yrs. It has 178k on it, but I believe the guy I bought it from said that he replaced the timing belt & head gasket just before I bought it with 158k on it. Anyway, that might be a little over my head skill-wise.

 

[hoe_nah]

okay if you want to find the source of the leak do a coolant pressure test...it'll show were the coolant is coming from

 

[Camokid84]

I work at a Toyota dealership and I mostly deal with newer vehicles, so I dont know if this advice applys to you situation but heres what I know. When a coolant leak is present you will see a coral looking crusty around the point of leaking. From what I understand between the heat, and the exposure to air causes this. Its an awesome way to find the source of the leak. Its a good idea to give the engine compartment a good look through, before throwing parts at it. You can do a radiator pressure test, but that only tells you that there IS a leak and not where it is.

 

[kzink]

I had the same thing happen it looked like it was coming from the tstat but couldn't really tell because it's so clustered up down there and the tstat mounts onto the waterpump ended up being a leaking waterpump

 

[Hyde802]

okay if you want to find the source of the leak do a coolant pressure test...it'll show were the coolant is coming from

I like this ideal. Find the leak and solve that issue before you start throwing parts at it.

 

[hoe_nah]

I work at a Toyota dealership and I mostly deal with newer vehicles, so I dont know if this advice applys to you situation but heres what I know. When a coolant leak is present you will see a coral looking crusty around the point of leaking. From what I understand between the heat, and the exposure to air causes this. Its an awesome way to find the source of the leak. Its a good idea to give the engine compartment a good look through, before throwing parts at it. You can do a radiator pressure test, but that only tells you that there IS a leak and not where it is.

true but if you suspect the thermostat then you can do the test and if you do lose pressure, just check the thermostat area as coolant will probably be dripping from the area...if not then you need to search a diff area

 

[gnuorder]

I think my 94 4runner has the same engine and I have the same problem. I replaced the tstat but it still leaks. I did notice one of the bolts was crusty and there was staining running down from that end of the tstat housing. I put anti seize on the bolts when I re-installed and that didn't make a difference. Could the housing itself be warped in either of our cases?

 

[Footofgod]

The 3.0 has as many coolant passages as it does vacuum hoses, that leak could actually be coming from several different spots in that area of the engine. Trust me, chased one for over a year. DO THE LEAK TEST! Be sure before you waste hours of time and hundreds of dollars trying to throw parts at it.

 

[gnuorder]

The 3.0 has as many coolant passages as it does vacuum hoses, that leak could actually be coming from several different spots in that area of the engine. Trust me, chased one for over a year. DO THE LEAK TEST! Be sure before you waste hours of time and hundreds of dollars trying to throw parts at it.

Thought this thread was recent. Anyway, I can see the leak, just not where it's coming from. I don't think a leak test will help in my case. It's dark now but tomorrow I'll take the housing completely off and look at it. I'll also try and get a mirror down there. I'm thinking from other threads that it's the water pump seal.