This time it's my cooling system..

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VDubbinIt
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This time it's my cooling system..

Post by VDubbinIt »

I noticed recently that my coolant temp seems to heat up faster than normal (as in, less than 10 minutes of driving) and stay either on the red light or towards the right side. That's when I'm driving. If I stop, it will get mighty close to the far right line. Normally, since it's winter, it'll stay on the left side of the light and barely start to get off the light before the fan kicks on and it cools down if I'm sitting at idle. All hoses, overflow tank and cap, thermostat and housing, water pump and housing have all been replaced in the last year. The fan still kicks on it's just that the coolant heats so quickly that the fan doesn't have time to cool it down. It hasn't actually overheated (the light hasn't flashed at me) and the engine is running at normal temp. Pressure test turned up with no leaks although I am getting coolant steam blowing in through the vents (which has only happened in the past with a leak so I don't understand that one). I've also always noticed that even after the components listed above were replaced, I still have small bits of coolant that leak out from the o/f tank cap.

I also checked my ignition timing that was just set by the local mechanic and they left it at TDC so I advanced it a tad to see if that would help and it hasn't.

Like I said, I let the car sit at idle and it doesn't overheat it just gets really hot :/

Could this be the heater core? Radiator plugged? Temp sensor? Fan switch in the process of going out?

UPDATE:
After running the car to check that the heater core was working, I finally was able to pinpoint where the steam was coming from. The radiator :banghead: Right in front of the fan. No leaks on the ground though.


Thanks guys,
Jess
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Briano1234
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Re: This time it's my cooling system..

Post by Briano1234 »

so you will be replacing the radiator.... :(
Briano

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VDubbinIt
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Re: This time it's my cooling system..

Post by VDubbinIt »

That's what I figured.. just needed a second opinion. It seems to be an easy enough task though that I should be able to do it myself. I'm also glad my cabby is not one with stock a/c.. the rad is cheaper :)
CalAltaDubber
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Re: This time it's my cooling system..

Post by CalAltaDubber »

I agree with Brian, sounds like a pin hole leak, although it is a very small leak, it is a sign that the rad is going to fail. Time to replace.

They are easy enough to change.

Since you are pulling the rad anyway, it would be a good time to flush the cooling system and replace the thermostat.
Phil

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eric4321
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Re: This time it's my cooling system..

Post by eric4321 »

Just fyi the ac radiator is slightly larger and a direct bolt in from what I have read. A non ac one will do just fine but if you want more cooling capacity you could "upgrade".
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Briano1234
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Re: This time it's my cooling system..

Post by Briano1234 »

Oh and check here or Kammy's for the trimming the radiator shroud as it makes playing with it later a hell of a lot easier. Sorry on a borrowed outer and free wi-fi....
Briano

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VDubbinIt
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Re: This time it's my cooling system..

Post by VDubbinIt »

Cool, thanks everyone.

The thermostat was replaced last year.

Also, would a pin hole leak make it heat up faster and run hotter in general? Or could it be something else as well?

The bentley makes the job sound easy, but are there pictures out there of someone removing the radiator on this car? I'm going to try and save $100 and do it myself :?
VDubbinIt
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Re: This time it's my cooling system..

Post by VDubbinIt »

Too many choices for radiators! Is there a particular brand that's better? I'm seeing a lot of Nissens (which is what the VW parts place here sells) and Spectra. Also saw one that's Behr.

Which one???
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kamzcab86
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Re: This time it's my cooling system..

Post by kamzcab86 »

VDubbinIt wrote:Too many choices for radiators! Is there a particular brand that's better? I'm seeing a lot of Nissens (which is what the VW parts place here sells) and Spectra. Also saw one that's Behr.

Which one???
Hate to say it, but there's also Valeo (that's what's in my '86; made in Italy; exact replacement). Have never used the others, so can't comment on them; Spectra manufactures fuel tanks for these cars as well.

And I thought Behr was in the paint business... :screwy: :mrgreen:
VDubbinIt
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Re: This time it's my cooling system..

Post by VDubbinIt »

Ha, me too. I used to work for Home Depot so I was a little confused that a radiator was the same brand as paint. I'm thinking of just going with the spectra. It has a 2 year warranty as opposed to the 18 month for a nissens and the price is not much different. They are both plastic w/ aluminum core. It's not really in my budget to get an all metal one :/

http://www.behr.de/Internet/behrcms_eng.nsf/
CalAltaDubber
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Re: This time it's my cooling system..

Post by CalAltaDubber »

VDubbinIt wrote:Cool, thanks everyone.

The thermostat was replaced last year.

Also, would a pin hole leak make it heat up faster and run hotter in general? Or could it be something else as well?
Any leak causes loss of pressure and the cooling system's ability to function properly.

Thermostats are cheap. When my family had the rad shops, we discovered that up to 30% of thermostats were faulty right out of the box, so the extra $10 shouldn't be an issue.

If you want to flush the cooling system, you need to pull the thermostat and replace the housing to perform the flush. Then you replace the thermostat.

As far as coolant goes, they are mostly the same, but I recommend Prestone, simply because it is yellow in colour. It makes it easy to tell if the coolant is dirty. Something hard to do with dark coloured antifreeze.
Phil

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'88 Cabriolet, "Posh Bunny"
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VDubbinIt
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Re: This time it's my cooling system..

Post by VDubbinIt »

Replaced the radiator and I still feel like it's running hotter than before but is technically normal. Once again, within ten minutes of driving, the line is already right on top of the red light, it will then go to the right side of the light before the fan comes on, but it generally stays either right on top of the light or on the right side, even when I'm on the freeway. Up until I noticed it getting hot, it used to stay on the left side of the light while driving on the freeway and would only go to the right side frequently if I were in traffic or stopped. I'm wondering if perhaps since the timing was off, it was running cooler than normal and now that the timing is set it's running normal? Also, since the timing belt was too tight after they set the timing, could it be that it's still a bit too tight? The radiator cap is less than a year old, but maybe it could be faulty? Temp sensor? Thermoswitch in the process of going bad (if that's possible)? Or am I just worrying for nothing :?: :?: :?:
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Briano1234
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Re: This time it's my cooling system..

Post by Briano1234 »

If you Flushed the system prior to replacing the rad, then it shouldn't be an issue however, I would go with a lower t-stat, and replace all the senders. Did you also check that the radiator fan and radiator fan switch was working?

The Gauges in the instrument pod do go flaky and cleaning the contacts and adding a new path to ground usually eliminates the flakiness.

Also if you haven't replaced the grounds on your car I have seen voltage spikes that make gauges read off, as well as senders......
Battery to frame and frame to engine/transmission.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:
VDubbinIt
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Re: This time it's my cooling system..

Post by VDubbinIt »

Didn't flush the system or change the t-stat :banghead: I had a "mobile mechanic" do it. I've always had good luck with them but this guy was.. yea, anyway, won't be calling him again. I originally wanted him to change the tstat too but I changed my mind after meeting the guy. After watching him though, I should be able to drain the coolant myself but I'm not sure how to do a flush on these cars. Like I said previously, the water pump, tstat and housing, all hoses, overflow tank, and rad cap have now been replaced in the past year. I'm pretty sure they did a flush when they changed the water pump 10 months ago. The fan works fine.. comes on when it's supposed to, goes off when it's supposed to. However, I read about testing the temp sensor and I'm confused as to what it's supposed to do if it's good or bad. I do know that if the fuel lines that are right by it, touch it, it shoots to the right and the light flashes like it's overheating.

Thanks for telling me about the grounds! I've always been confused as to what and where specifically the grounds are. I will def. check those out.

BTW, it's been almost a year since I've had this car and I'm not giving up! I still have a lot to do... I'm pretty sure the fuel pump is going, possibly the clutch, o2 sensor could use a replacement, fuel injectors, valve cover gasket (still haven't tried messing with the stripped nut but I may tackle that soon)... I'm sure I'm forgetting something.
If it weren't for you guys here though, I probably would have given up a long time ago. I can't thank you guys enough for being so willing to help so many like me that don't know what the f they're doing :)
CalAltaDubber
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Re: This time it's my cooling system..

Post by CalAltaDubber »

VDubbinIt wrote:Didn't flush the system or change the t-stat :banghead: I had a "mobile mechanic" do it. I've always had good luck with them but this guy was.. yea, anyway, won't be calling him again. I originally wanted him to change the tstat too but I changed my mind after meeting the guy. After watching him though, I should be able to drain the coolant myself but I'm not sure how to do a flush on these cars. Like I said previously, the water pump, tstat and housing, all hoses, overflow tank, and rad cap have now been replaced in the past year.
In that case, since it is all put back together, I'd just leave it unless there is still cooling issues. If it ain't broke...

I only suggested it because you mentioned that you were pulling the rad.

VDubbinIt wrote:BTW, it's been almost a year since I've had this car and I'm not giving up! I still have a lot to do... I'm pretty sure the fuel pump is going, possibly the clutch, o2 sensor could use a replacement, fuel injectors, valve cover gasket (still haven't tried messing with the stripped nut but I may tackle that soon)... I'm sure I'm forgetting something.
If it weren't for you guys here though, I probably would have given up a long time ago.
Hang in there, these cars are not getting any younger. Once you have spent some time working on it you will find they are actually very simple to maintain. Problem is you need to work out all the bugs left by previous owners.
VDubbinIt wrote:I can't thank you guys enough for being so willing to help so many like me that don't know what the f they're doing :)
Hey that's what this forum is all about. We are glad to have you here.
Phil

'87 Cabriolet, "Topless Bunny"
'88 Cabriolet, "Posh Bunny"
'04 Golf
'12 Golf Wagon TDI
'69 Manx type Dune Buggy (New Toy)

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