1G Overheating with scirocco radiator

[govproperty]

I am having a problem with overheating during long trips or if I am running a lot of errands. I added to heater core back into the loop recently as well. Within the last year or 2 have have replaced to theromstat (180*), water pump, and the radiator cap. The wiring for the thermo switch for the fans was too short so there is one 14" fan wire to stay on. The car has a scirocco radiator in it with -16an lines with a front mount intercooler and aftermarket power steering cooler on it. The car hasn't been driven much so I am not sure what if any changes brought this on. Is there any way to check to see if the radiator is just to small to cool the car when driven daily? Oh, I forgot to add the compression was around 150 across all the cylinders so I don't suspect the headgasket but it is still possible.

 

[craig4g63]

I am having a problem with overheating during long trips or if I am running a lot of errands. I added to heater core back into the loop recently as well. Within the last year or 2 have have replaced to theromstat (180*), water pump, and the radiator cap. The wiring for the thermo switch for the fans was too short so there is one 14" fan wire to stay on. The car has a scirocco radiator in it with -16an lines with a front mount intercooler and aftermarket power steering cooler on it. The car hasn't been driven much so I am not sure what if any changes brought this on. Is there any way to check to see if the radiator is just to small to cool the car when driven daily? Oh, I forgot to add the compression was around 150 across all the cylinders so I don't suspect the headgasket but it is still possible.

What is your coolant to water mix ratio?

Any coolant additives?

Do you have any ducting to direct airflow through the radiator?

 

[govproperty]

I have about a 50/50 mix of coolant to water with no additives. Currently there is no ducting to the radiator. I have considered making some ducting but since I haven't seen a lot of people daily driving with scirocco radiators I am not sure if it will work. I hadn't originally planned to daily the car but school wants my money and it is decent on gas. However, I don't want to build ducting just to have to toss it later. But if that is all it needs that would be great.

 

[craig4g63]

I have about a 50/50 mix of coolant to water with no additives. Currently there is no ducting to the radiator. I have considered making some ducting but since I haven't seen a lot of people daily driving with scirocco radiators I am not sure if it will work. I hadn't originally planned to daily the car but school wants my money and it is decent on gas. However, I don't want to build ducting just to have to toss it later. But if that is all it needs that would be great.

Do the simple things first. Start with an 80/20 mix of water to coolant and add in Redline water wetter. This may solve your problem. If temps are still climbing, add ducting to direct airflow.

 

[govproperty]

Thanks, I'll try that out and see where it goes.

 

[Jermoturbo]

How does the scirocco rad sit in the engine bay compared to your thermostat housing? If it sits higher than the thermostat housing, you'll never be able to bleed all of the air out of the system.

 

[govproperty]

I believe it is lower but I'll check again to make sure. Since I last posted I have changed the coolant to water ratio to about 20% coolant and 80% water. I pressure tested the system and the did appear to have a very slow bleed down on the needle but I couldn't find any leaks. I have considered that the headgasket could be bad but I don't want to jump to conclusions before there is more evidence. Since I had the tester I also checked the radiator cap and found that it was only holding 5 psi and it was only a week old. So, I just installed mishimoto 19 psi cap to fix that. I haven't test it out yet since I am going to install a saturn alternator this weekend (mine is only putting out 12v). However, I don't believe that the alternator is related to the overheating issue since there is not a significant rise in temperature when I am at idle.

 

[1qkfwd]

There are a few different radiators for the Scirocco. Which one do you have? Also whats your exhaust routing and are you running an external dump?

 

[907dsm]

^^ Very good point about the external dump, I have one as well and never realized that affected my coolant temps as well.

One of my biggest issues was proper ducting, I'd highly suggest that if that isn't addressed already.

 

[94awdcoupe]

ducting is super important on a 1g. it has the smallest opening for airflow. once that is restricted with an intercooler, airflow to radiator suffers.

 

[4g63t]

Is your fan pushing or pulling? Pulling works best. Is it a cheap aftermarket fan from a parts store? I had two of those pushing and my car would run hot in the summer.

I got a real FAL fan to take the place of the two aftermarket part store fans and have ran cool ever since. I would of never thought that it would make that much of a difference but it did.

 

[Kapok6]

do you have small white bubble coming up to the radiator cap when at operating temp and you pull the cap off? If so, that is usually indicative of an HG leak.

Also, is you car auto or 5spd? Mine is auto and I had an issue with the aftermarket trans cooler that was placed between the fmic and the radiator dumping tons of heat right in front of the rad. Once I moved it, and added some ducting, my overheating issues went away.

 

[govproperty]

I have also been having some intermittent cranking issues lately and today the fuse block that I was using to replace the factory one for the 3 fuses on the battery melted. It had to have been a loose connection to create that much heat but the screw was still tight when I took it off. Anyway, yesterday it overheated again and by the time I pulled over it was at 225. I do not remember what type of fan it has on it but it is installed as a puller. I have been talking with some guys at work about building a shroud for it. Also, it is a 5 speed with a recirculated tial wastegate. However, it does have small oil cooler that is being used as a power steering cooler right behind the radiator. As soon as I get the distribution block in I will check for signs of a bad headgasket and build some ducting for it.

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