*!Build of the year candidate!* Strange PNW Build: E30+Volvo

[adam.nonis]

Heat shields and starting of an expansion tank.

[LJ851]

So, I think I killed my fan clutch last night. I was doing a bunch of service stuff (timing belt, tensioner, cam seals, water pump, hoses and belts) and while I had the fan off I degreased it and scrubbed it down. Last night on the way home it started running hot. Since I replaced the thermostat a while back, it hasn't run anywhere but dead straight up once it warms up. I got home and started trying to think through the possible issues. Air pocket, too much anti-freeze/not enough water, etc. I'm pretty good at getting all the air out of the system, so I don't "think" it's that. On the way to work this morning, if it would start running hot, I'd shift into a lower gear and bring the RPMs up and it would start cooling down (I know that technically decreases load, but not much on a flat road). Once I got to work I popped the hood and while it was still hot (car off), I could freewheel the fan with ease. When it's warm, isn't that when the fan should lock up and be closer to 1:1?

If the temp is above normal (half way on the gauge) the fan should be pretty rigid to the W/P shaft. Coolant not flowing through the radiator properly from a bad thermostat or an air bubble will cause the radiator to stay cool and thus not activate the fan clutch even though the engine is hot.

[adam.nonis]

If the temp is above normal (half way on the gauge) the fan should be pretty rigid to the W/P shaft. Coolant not flowing through the radiator properly from a bad thermostat or an air bubble will cause the radiator to stay cool and thus not activate the fan clutch even though the engine is hot.

Ok, how about this, in any driving scenario (freeway driving, side roads or parked) when it starts to get warm, if I increase the RPMs (by downshifting while driving or more throttle while sitting) the temp comes back down. The things I changed this when this started was: timing belt, tensioner, cam seals, water pump and hoses. Previous to this round I put in a new thermostat and brand new radiator. After the thermostat and radiator the gauge was dead solid 12:00. The new water pump had a metal impeller while the old one was plastic (and a slightly different shape, I think). Any chance the new water pump is less efficient and requires more RPM to pump the same amount? I’m going to put the old pump in tomorrow after work to test the theory. Just curious your thoughts.

[Digitalwave]

If the temp is above normal (half way on the gauge) the fan should be pretty rigid to the W/P shaft. Coolant not flowing through the radiator properly from a bad thermostat or an air bubble will cause the radiator to stay cool and thus not activate the fan clutch even though the engine is hot.

What does the radiator have to do with "activating" the fan clutch? The fan clutch is a viscous coupling. The cooler it is, the more it "free wheels." The hotter it gets, the more it spins (more like 1:1 as he mentioned).

Ok, how about this, in any driving scenario (freeway driving, side roads or parked) when it starts to get warm, if I increase the RPMs (by downshifting while driving or more throttle while sitting) the temp comes back down. The things I changed this when this started was: timing belt, tensioner, cam seals, water pump and hoses. Previous to this round I put in a new thermostat and brand new radiator. After the thermostat and radiator the gauge was dead solid 12:00. The new water pump had a metal impeller while the old one was plastic (and a slightly different shape, I think). Any chance the new water pump is less efficient and requires more RPM to pump the same amount? I’m going to put the old pump in tomorrow after work to test the theory. Just curious your thoughts.

With an M20, I would always start by re-bleeding the system. Have the car on an incline, nose up. Do you have a heater core?

I seriously doubt it's the water pump. I would not go through the effort of putting the old one back in.

Have you done the "newspaper" test on the fan clutch?

[adam.nonis]

What does the radiator have to do with "activating" the fan clutch? The fan clutch is a viscous coupling. The cooler it is, the more it "free wheels." The hotter it gets, the more it spins (more like 1:1 as he mentioned).









With an M20, I would always start by re-bleeding the system. Have the car on an incline, nose up. Do you have a heater core?



I seriously doubt it's the water pump. I would not go through the effort of putting the old one back in.



Have you done the "newspaper" test on the fan clutch?

I had the nose so high in the air I thought it was gonna tip over backwards..lol. I could bleed it on an incline AND jacked way up.

I do have a heater core. Blows hot air.

When I crack the bleeder, there’s no bubbles just a stream of water right away. The return line that goes to the expansion tank has a solid stream with no bubbles either.

I don’t know what the newspaper test is (I’m an E30 newb), but I just replaced the fan clutch with no real change.

[adam.nonis]

Here’s the one I pulled off my car.



No shaft play. No issues, I just swapped cause I had it apart.

Here’s an online picture of what I put in.

[nando]

I had the nose so high in the air I thought it was gonna tip over backwards..lol. I could bleed it on an incline AND jacked way up.

I do have a heater core. Blows hot air.

When I crack the bleeder, there’s no bubbles just a stream of water right away. The return line that goes to the expansion tank has a solid stream with no bubbles either.

I don’t know what the newspaper test is (I’m an E30 newb), but I just replaced the fan clutch with no real change.

the newspaper test is basically when the car is warm, stick a newspaper in the fan and see if it stops. If the fan clutch is good it shouldn't.

[adam.nonis]

[ForcedFirebird]

Don't even need to put an e30 in the air. Just unfasten the expansion tank and lift it. Same thing. I actually have a coolant funnel that fits the fill hole tight and can get the coolant level far above the engine.

Do the newspaper test. I bet the fan clutch was on it's way out and just the fact of being apart may have done it in. It's common to do the pump and fan clutch at the same time.

I always drill a small hole in the t-stat too. Not only keeps some coolant circulating, makes it easier to bleed.

EDIT: What brand was the pump you went with?

[LJ851]

What does the radiator have to do with "activating" the fan clutch? The fan clutch is a viscous coupling. The cooler it is, the more it "free wheels." The hotter it gets, the more it spins (more like 1:1 as he mentioned).

The fan clutch is heated by the hot air created by the radiator, not from the heat of the water pump.

[LateFan]

I always drill a small hole in the t-stat too. Not only keeps some coolant circulating, makes it easier to bleed.

Where do you put the hole?

[adam.nonis]

Don't even need to put an e30 in the air. Just unfasten the expansion tank and lift it. Same thing. I actually have a coolant funnel that fits the fill hole tight and can get the coolant level far above the engine.

Do the newspaper test. I bet the fan clutch was on it's way out and just the fact of being apart may have done it in. It's common to do the pump and fan clutch at the same time.

I always drill a small hole in the t-stat too. Not only keeps some coolant circulating, makes it easier to bleed.

EDIT: What brand was the pump you went with?

I already replaced the fan clutch. Should I check the new one?

I did drill a hole in the thermostat when I replaced it a few months back

GEBA. It was listed as “OEM” through WorldPac

Where do you put the hole?

Basically right through the arrow that points up.

[adam.nonis]

https://youtu.be/7PH24okuz58

This was while parked, but it’s basically the same scenario while driving if I downshift. I give it some gas and the temp comes down. I give it more gas and it comes down more. At this point I REALLY don’t want to tear it all down again, so I’m going to try multiple bleeding techniques and see what I can come up with prior to trying the old pump.

[flyboyx]

I don't think bleeding is the issue. it sounds like you are air bubble free. are you sure its even overheating? have you checked your temp with a thermometer gun? its possible your brown sending unit on the t-stat housing is bad.

here is a long shot, but it is also possible that your thermostat is sticking. judging by your symptoms, this is a bit unlikely. even though its new doesn't mean that its good.

[adam.nonis]

I don't think bleeding is the issue. it sounds like you are air bubble free. are you sure its even overheating? have you checked your temp with a thermometer gun? its possible your brown sending unit on the t-stat housing is bad.

here is a long shot, but it is also possible that your thermostat is sticking. judging by your symptoms, this is a bit unlikely. even though its new doesn't mean that its good.

I added an aftermarket gauge and I’m going to monitor it. I think as long as it’s +/- 200°F it should be ok. Thermostat is a cheap easy part to try as well.