Interior leak and overheating

CarlaRWG · Post by **CarlaRWG** » Mon Mar 13, 2006 8:41 am

I discovered a very small (1 drop every 20 minutes)amount of radiator fluid coming out of the heat box, after much discussion with my better half it was decided to run the car for a while to see if the leak gets bigger or goes away. (My husband thinks the leak came from being jacked up several times, I think that should not affect the car)

Anyway, the car got hot after 5 - 7 minutes (not good), the moisture was back but it was cold water not hot! The PO said he replaced the water pump and Ed is thinking its the thermostat.

I'm asking for opinions

What would cause cold drops to come from the heater box and cause the car to overheat?

Danno · Post by **Danno** » Mon Mar 13, 2006 9:44 am

clogged system, thermostat not opening up. I've not looked at our thermostat, but I know a trick that works for my other car. you put a pot on the stove and start heating some water with the thermostat in it. monitor the temp with a candy thermometer or whatnot and see what temp it opens up at. if yours doesn't open up at all, or opens at some ungodly temp then that's your problem. I don't have my manual here with me at work, what temp are we talking here for the thermostat to be fully open? 190F? 200F? anyway, probably somewhere in there.

mdrburchette · Post by **mdrburchette** » Mon Mar 13, 2006 9:54 am

You can check the thermostat easily enough by putting it in a pot of water with a thermometer and heating the water to see when it opens up. You may have an air bubble in the system if it jumps to red after 5 to 7 minutes. Some people have a hard time burping the air out of a Fiat since the radiator is not the highest point of the cooling system.

mdrburchette · Post by **mdrburchette** » Mon Mar 13, 2006 9:55 am

Oops, must have posted at the same time.

Danno · Post by **Danno** » Mon Mar 13, 2006 10:02 am

haha, i guess so. it's nice to show that it's the way to do it though!

good call on the air bubble, could be the problem.

Have you drained the old fluid out? I'd do that, flush it with distilled water a couple of times and then refill. Run it for a few seconds with the water in there to help get the old out.

So Cal Mark · Post by **So Cal Mark** » Mon Mar 13, 2006 10:25 am

you should pressure test the system to find the source of the leak. If it's coming from the right side of the heater, the most common culprit is the heater control valve. The heater core may also have a leak, but the valve is a much more common problem. As mentioned previously, air in the system will prevent the thermostat from opening. If the system was low, adding water will not get the air out. The easiest way to bleed the air out is to remove one of the water lines from the choke and fill the system thru that hose until no more air bubbles come out.

One trick lots of owners have done is to add a flush tee to the heater hose just over the valve cover. You can buy the flush tees for a couple of bucks at any auto parts store, Then fill the system thru the tee.

For a temporary fix, bypass the heater by connecting the 2 heater hoses together. Jacking the car up shouldn't have any effect on the cooling system unless you put the jack under the radiator

Danno · Post by **Danno** » Mon Mar 13, 2006 10:56 am

So Cal Mark wrote:Jacking the car up shouldn't have any effect on the cooling system unless you put the jack under the radiator

what, so that's NOT where I should put the jack? CRAP, BRB.

So Cal Mark · Post by **So Cal Mark** » Mon Mar 13, 2006 3:33 pm

it may seem obvious, but you'd be surprised how many cars I see that have been raised from either the oil pan, radiator or rear trailing arm

Mad-Machine · Post by **Mad-Machine** » Wed Mar 15, 2006 8:33 pm

I had a shop once use their lift on my brand new trailing arms.. bent both long ones nicely...

I would definatly check the heater control valve..

mlynch003 · Post by **mlynch003** » Fri May 26, 2006 6:07 pm

A major source of leaks and the cause of many heater valve replacements is the gaskets that seal the valve to the core. My wife's Spider went to pouring antifreeze into the passenger floorboard and the new carpets. I thought the valve was bad, but took it apart first. All that I needed was to replace the rotted cork gaskets on the heater control valve. One Fiat Spider, better than new since I made the gaskets out of good thermostat gasket material instead of cork. Also added some o-rings into the space for a backup. One issue that this leak creates is the fact that the cooling system will not function correctly with the coolant leak. If coolant gets out, air can get in and the system will constantly have air entering and building up. The Flush tee works best for filling and purging air from the system. Stop the leaks in a SPIDER cooling system and the thing will run forever and NEVER get hot!

So Cal Mark · Post by **So Cal Mark** » Fri May 26, 2006 7:14 pm

the oem Fiat heater gaskets are neoprene (rubber) with a raised bead that acts as an o-ring. Your cork gaskets must have been aftermarket or home made

Mad-Machine · Post by **Mad-Machine** » Sat May 27, 2006 10:04 am

this is not to say that the stock rubber gaskets cannot dryout, crack, and start leaking... but usually the diaphram in the valve goes first.

Or, if you are unlucky like me.. you heater core can fall onto the fan and the spindle in the middle of the fan can eat a hole in it.. I spent an entire winter without heat because of that.. back when my spider was my ONLY car. I wouldn't worry too much about it though.. seems the PO had cracked the heaterbox and that was let it fall down.

mlynch003 · Post by **mlynch003** » Tue May 30, 2006 3:11 pm

The operative word here is Previous Owner. So. Cal Mark I'm sure is correct, my gaskets were likely home made, they looked odd. I fabricated my own gaskets and added the o-rings as a backup, I had no idea that the original design used a "molded in " o-ring. If not for Previous owners I would no have had any work to do. My 82 Spider was a total mess due to the efforts of the P.O.! Seems like too many Fiat Spider owners think that just because they buy a Fiat that this somehow magically transforms them into a mechanic. Buying the car and the parts does not make you a mechanic! Most P.O.'s need to have their toolboxes taken away! I spent many hours "repairing" the PO "repairs". Anyway hope you get your Spider back on the road! Good Luck!

So Cal Mark · Post by **So Cal Mark** » Tue May 30, 2006 3:27 pm

I think there are a couple of reasons that Fiats get tinkered with by owners; one is that many people buy these cars very cheaply whether by necessity or luck and may not have the means to have them repaired; two, in some locales it's nearly impossible to find anyone who can or will work on them.
IMHO, this is what led to Fiats' poor rep in the US, many of these cars just weren't repaired properly and it made them even more undependable

chrisg · Post by **chrisg** » Sun Jun 04, 2006 7:48 am

Maybe with the prices of FIATs continuing to rise, maybe we'll start to see the the loss of the super-cheapskate maintenance plans that killed so many good FIATs over the last 20 years or so.

Interior leak and overheating

Interior leak and overheating

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