Temperature above 190.....

Wayne

True Classic
I'm gonna be on this Workshop forum frequently now. Summer is around the corner got hot the last week and the radiator fans don't seem to kick in. Check Fuse N (16amps) and thermostat (location?) ? I can't even see the fans....I'd have to be under the car. I'm not even sure the gauges read accurately.
 
I'm gonna be on this Workshop forum frequently now. Summer is around the corner got hot the last week and the radiator fans don't seem to kick in. Check Fuse N (16amps) and thermostat (location?) ? I can't even see the fans....I'd have to be under the car. I'm not even sure the gauges read accurately.
If you haven‘t seen the ‘Wheeler Dealers’ episode on the X1/9, on Motortrend TV app, the cooling system is extensively covered. Will give you some ideas...
 
Testing the fan is done by simply unplugging the sensor from the left end of the radiator and putting a test lead across the two contacts, this will cause the fan to turn on. Often times the sensor in the radiator is defective and must be replaced.

If the fan is running and it is an OE fan, you will know when it turns on, there is a definite vibration you can feel in the car.

The gauge is likely inaccurate in its exactness but it is indicating generally what is going on. They are all a bit different but they work well enough. If it is going into the danger zone I would believe it.

The fan doesn’t run often on my car in my climate, I can drive home for 20 minutes in 80 degree weather and it won’t run at all. If I run into a bit of traffic it may come on for the time I am stopped or after coming off the highway and waiting at a light as the car sheds the heat from running hard. In stop and go traffic you should sense the fan running periodically for short periods.

Some put a switch acting on the relay to force the fan to run as desired, in general it isn’t needed but it gives them peace of mind.

It is also possible to install a second fan which could be controlled by using a VW thermo switch in the radiator (they are the same size and thread) which when wired properly can use a second relay to start the second fan at a higher temperature. The VW sensor can be had with several temperature ranges for the two startup temps.

You may have a lot of air in the system causing your high temps and making it so the radiator fan won’t come on but it is unlikely to have that much air in the system.

Draining, flushing and refilling the coolant system is a good idea. Pay careful attention to bleeding the system as it is more involved than some other cars as the remote radiator has an air bleeder in the top left corner reached through a hole in the front trunk.
 
My temps seem to be related to time driving, not speed. I'm solidly below 190 for about 20-25 minutes, and then I start to creep up. Often hits 190, sometimes starts creeping over, but not in the red. When it goes above 190 I put on the heater and it goes down to 190. I driveway-tested the fans at idle and they definitely come on. The seller told me he changed the fluid, and its clear, but I'm wondering if he lied. If so, its at least 25 year old antifreeze. Guess that's the place to start!
 
My temps seem to be related to time driving, not speed. I'm solidly below 190 for about 20-25 minutes, and then I start to creep up. Often hits 190, sometimes starts creeping over, but not in the red. When it goes above 190 I put on the heater and it goes down to 190. I driveway-tested the fans at idle and they definitely come on. The seller told me he changed the fluid, and its clear, but I'm wondering if he lied. If so, its at least 25 year old antifreeze. Guess that's the place to start!
The radiator could need flushing or reaming out if really bad.

I bought flush fluid at NAPA to run through my whole system with distilled water to try and get some of the built up crud out of my ‘85’s system. I am taking the entire system apart just to clean it up, I don’t have any cooling issues aside from a dead thermo switch in my radiator which will be getting the VW upgrade so I can add the second fan.

You can also buy industrial grade vinegar in different concentrations that you could run through the system if also replacing all the hoses. I have been going back and forth on this as I don’t want to create a problem but if it is what is needed. Suffice to say I will use the Napa material first and if I find things are really crudded up may try something more drastic and then deal with the consequences.

Basic maintenance is always a good place to start from, you always learn something and find other things to fix. The Previous Owner is always to blame (or whatever idiot mechanic they employed) for anything you find :) I never find anything I did in the distant past to ever be even slightly hinky. Cough Cough…
 
Mine acted similarly the day I bought it, the test drive was fine, hPO drove it to my house, about 20 minutes in local traffic, it overheated and puked out rusty water. Still bought the car, price dropped a little in the driveway. I thought it was just leaking out and ran low on water. Old school older guy, barley ever drove it for years and was running on almost pure water. Replaced cracked expansion tank, flushed rivers of rust out best possible and filled with good old green antifreeze50/50. Ran fine on short trips around town, but after about 40 minutes of running on a warm day, temp went up slowly and steadilly, so I parked it just before full overheat drama. We came back after dark and the air temperature dropped and refilled and drove home. Ran cooler, but not quite normal. I replaced the radiator with an aluminum unit and flushed it even more. It has been fine since. Old radiator weighed a TON, once radiator was out, flushing got clear water pretty quickly.
 
Got a coolant leak dripping down to oil pan area. Can't really see where at the moment...
Check the vent ("weep") hole on the water pump. It's behind the pulley near the shaft, on the bottom of the "snout" that sticks out from the pump body.
 
When it goes above 190 I put on the heater and it goes down to 190.

Yep, my car does this as well - "burp" the system, make sure there is no air in there. If you lose heat at idle, that means there is a large air pocket in the system. You can bleed off the air out of the radiator - careful when doing this while the system is pressurized! (I've done it... Just a small amount of turning of the bleeder will allow the air to escape).

I think my rad is plugged. It's original.. and the current owner didn't change fluid on time - so.. most likely it's plugged. It's NOT fun turning on the heater during a hot summer cruise, lol.. :)
 
Does it mean a replacement?
As a water pump seal wears it allows some fluid to seep past it. The vent/weep hole gives that fluid a place to escape from. So if the leak is coming from there (verify that first), then it is a sign the pump seal is wearing out. How long will it last? No telling. Is the rest of the pump (impeller, etc) still good? No telling. The only way to find out the exact condition of the pump is to remove it. But at that point you may as well replace it.

Another common sign the pump is wearing out is the bearing (bushing) begins to make some noise. As it gets worse the pulley will even begin to wobble. If any of that is happening then replace the pump now....it's more than a slightly worn seal.

If the leak is very minor and there is no problem with the cooling system maintaining proper operating temperature, then you might let it go a bit longer. However the seal will continue to wear and leak more over time. So eventually it will need to be replaced. But verify that's what the leak is first.
 
Before I do a flush and fill (per my post above), I wanted to test when the fans came on, so I let the car sit in the driveway for a while after a few mile ride. The picture below shows where they kicked in. That seems very high since everyone talks about their temps being under 190, but I see Dan S. posted the values below from the manual in another thread which shows they're in line. Does this look right?

Thermostat:
Starts opening: 172° to 183° F
Fully open: 194° to 201° F

Cooling fan thermoswitch:
Cut-in: 198° F
Cut-out: 189° F
 

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Before I do a flush and fill (per my post above), I wanted to test when the fans came on, so I let the car sit in the driveway for a while after a few mile ride. The picture below shows where they kicked in. That seems very high since everyone talks about their temps being under 190, but I see Dan S. posted the values below from the manual in another thread which shows they're in line. Does this look right?

Thermostat:
Starts opening: 172° to 183° F
Fully open: 194° to 201° F

Cooling fan thermoswitch:
Cut-in: 198° F
Cut-out: 189° F
If that is the highest temp you see and that is at idle with the fans running. I think you are OK. Certainly wouldn't hurt to crack open the rad bleeder and check for air.

Just as a sanity check of the stock gauge, use a infrared thermometer to shoot temps around the block, head, etc. Take the temp of the sender in the block and see how it compares to what the dash gauge says.
 
Before I do a flush and fill (per my post above), I wanted to test when the fans came on, so I let the car sit in the driveway for a while after a few mile ride. The picture below shows where they kicked in. That seems very high since everyone talks about their temps being under 190, but I see Dan S. posted the values below from the manual in another thread which shows they're in line. Does this look right?

Thermostat:
Starts opening: 172° to 183° F
Fully open: 194° to 201° F

Cooling fan thermoswitch:
Cut-in: 198° F
Cut-out: 189° F
Remember that the gage is giving you a true reading of the coolant temp at the cylinder head. The coolant fan switch is all the way up front on the "cooler" side of the radiator, so there is a bit of latency that one must accept as normal especially under low flow conditions---both in terms of coolant flow rate from rear to front and cooling-air-flow-thru-the-rad----which is at its height when idling and not moving.

Don't make the mistake of expecting your 100% analog X1/9 instruments act like the modern "instruments" in a new car. Newer car instrument panel gauges display what the programmers of the various body and engine control modules want you to see.

Each hash mark on the gauge is 5 degrees, so that pic shows a reading of around 205-210. I agree with Karl you want to do a couple of bleedings to ensure the system is air-free, and you might see that drop maybe one hash mark. If that's as hot as you can get it, and reasonably thorough troubleshooting says all else is good (no visible leaks, no leaks when using a pressure tester, fan system proved good), then I'd say declare this to be normal for you car and enjoy!

If you really want to obsess over it, perhaps install a slightly lower temp-setting coolant fan switch or one of those two stage switches people are always talking about but never post the part number for!
 
If you really want to obsess over it, perhaps install a slightly lower temp-setting coolant fan switch or one of those two stage switches people are always talking about but never post the part number for!

251959481K​

There are others with a different connector with two other connector form factors available.

If you set it up to ground the relays the switch will tend to last longer.
 
Despite the factory specifications being what they are, I'm of the opinion that any old car should be kept a bit cooler than that. They do not have the design, engineering, materials, quality of newer cars that run at higher temperatures. Running cooler will improve reliability and help avoid failures.

If you want to keep the running temperature a little lower I'd recommend that the thermostat also be replaced with a slightly lower rating to go along with the lower temp fan switch. Those two components need to work together to be effective at controlling engine temps.

There is an entire discussion about the VW fan switches, with lots of part numbers for a selection of heat ranges, including the part numbers for the matching electrical connectors.
 
The reality is the temp at the engine versus the temperature at the lower portion of the radiator are very different things. Using the OE engine thermostat I think is the right thing to do, keeping the engine at the designed temperature is not a problem.

When the car was designed and built there were not multi temp switches in broad use, at the time most cars used a fan which turned when the engine ran because it was mounted to it. The turn on temps for the fan were appropriate for where they developed the car: Italy. Back then Bertone did not bring X’s to the American southwest to test the hysteresis of the cooling system so we end up with a marginal ability to pull the system down to proper temp once it gets out of a certain range. This is exacerbated by the age of the parts which today are compromised by deposits in the system and modern replacement parts which do not meet OE specs (water pumps in particular).

Providing cooler water to the engine from the radiator will better allow the correctly rated thermostat to properly hold the engine at that temperature and the cooling ability of the system will be better by a. keeping the base line temperature lower and b. providing greater cooling capacity by adding a second fan which runs when the system is getting beyond the intended capacity to shed heat.

Consider this other bit of reality: on an X (without AC) as delivered, the likelihood of the fan running, ever, when the car is actually moving at speed and the ambient temperature of the air is less than 100°, is likely very close to zero.

Most Xs are being run within those parameters most of the time. Yes, there are those of us who live in deserts, at high altitudes and suffer stop and go traffic. For those who live in those places, it is worth modifying parts of the system to better meet those demands. A second fan, a two temperature radiator switch and moving the fan turn on temps lower should provide the sufficient capacity to keep your X cool. After that it would be to increase coolant flow which will be a bit more involved to complete.
 
Agreed, all of this depends on several conditions of the particular situation. Although the concern here is that the gauge shows the engine running hotter than he desires. So apparently something in his situation needs to be improved.

Even if the radiator has ice cold water coming out of it, but the thermostat is a 190 degree (for example) rating, then the engine will still be 190 (or more). And since the dash gauge reads the engine (not radiator) temperature, the gauge will still show high because the engine is. So if the goal is to keep it running below 190 degrees then the thermostat needs to be changed to a lower temp rating. However the reason I say the radiator switch and thermostat need to work together is a cold rad switch and hot T-stat will make the fans run more (when going less than freeway speeds) trying to keep the radiator cool when the engine doesn't need and can't use it.

On the other hand, if the radiator switch is 200 degrees and the engine thermostat is a 180 degree unit, then the engine will never get down to 180 degrees (except at freeway speeds). So again the two components need to work together. But keep in mind the radiator temp switch only controls the fan. So if the radiator is only able to maintain 200 degrees despite a 170 degree rad switch, then the radiator is not able to exchange enough thermal energy, and neither the thermostat nor the radiator fan switch will help.

Same for everything else; water pump, coolant tubes, fan(s), etc, all factors need to work in unison to maintain equilibrium of the engine temperature.
 
Remember these are analog gauges and analog sensors, what they show is relative. The engine could well be at 190 (or 220 for all we know) or not depending on its accuracy.

Yes if the thermostat is made to hold 190 then hopefully it will hold the engine close to 190 by introducing the ice cold water as needed to the engine to keep it at 190. 190 is not high, it is proper and correct for this engine.

The radiator and the fan can keep it at 190 in all but the worst conditions: at idle, just coming off the race course/highway/autox. Or perhaps Lost Wages :)

The radiator on an X in good condition has never been the thermal weakpoint in the system, yes it could be better but it is more than enough to dissipate the energy dumped into the coolant by the existing engine.
 
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