A 355 Coolant Leak Question

to access the thermostat, unscrew the 6 nuts that hold on the plastic cover that covers the coolant reservoir and power steering reservoir. Once that is off, you can move the PS reservoir out of the way, or completely drain the fluid, remove the lines, and take the reservoir out completely. we also removed the bonnet for easy access. you should have an easy view of the thermostat from there.

i cant help you with diagnosing your problem though, i just thought id help you get access to the thermostat. since the leak only occurs once the passenger fan turns on, it might be related to the thermostat opening.
sorry i cant be more helpful.

 

If it's bubbling out the top of the radiator itself in front of the wheelwell, and not from a hose, it's probably a separation between the tank and cooling fins, unrepairable. New radiator. Bummer.

 

Are you sure it's not overfilled? The cooling system will purge any extra coolant if you over fill it. (not that I recommend this method of figuring out how much should be in there).

The owner's manual is a bit vague about how much coolant should be in the tank. It says to measure from the top, but it's not clear if it's the top of the threads or the top of the tank (which is about a 2cm difference). When I look in mine (1995 355 Spider) when it's cold, it's normally fairly low. Maybe 2-3cm from the bottom. Whenever I try to set it higher than that, it just purges until it gets back to that same level.

 

Mine did that because I overfilled it.

 

The thermostat is not on top of the right radiator.

 

Yes, but when overfilled, it should not leak out the top of the right radiator, as the OP is describing. It should come out the overflow hose on the expansion tank.

 

I think your problem is the radiator cap. You cannot see the thermostat housing unless the top cover piece is off so it unlikely to be coming from there. I had a similar problem and bought a new cap which solved the problem.

Also, when engine is cold check the level of coolant in the tank. It should not be filled to the top of the tank. If you stcik your finger in you should judt be able to touch it and this is the right level.

Goodluck!

 

The OP says the leak is from the top of the right side radiator...the cap is on the expansion tank on the top of the engine.

I would suspect he either has a leaking hose on the radiator, or a crack in one of the tubes brazed onto the top of the radiator.

I am also wondering if the OP is describing the problem incorrectly, and when he says "... bubbling out of the top of the radiator..." he means the expansion tank?

 

Yes you are right. Unles he took the rear splash wells off it is pretty hard to see the top of the radiator even when looking through the top of the engine.
He must be talking about the cap on the expansion tank.

It would be good if he took a pic of the problem to get a better diagnosis

 

IF, he is describing fluid coming out of he expansion tank, he should not visibly see bubbling, since it should pipe down the small overflow hose. So, either the hose is missing, or the cap may be bad.

I would start with making sure the coolant level is correct, or close to correct. When cold, the level should be no higher than 6cm below the top of the filler neck on the expansion tank. Some cars will spit and puke coolant even at that height, and prefer a couple cm lower. If an equalibrium cannot be found, then a new cap may be in order.

 

Shawn, please note my post #13 on setting the proper level. Is the fluid going down the overflow hose or right around the seal on the cap? I do think you may need a new cap, but understand if you overfill the expansion tank, it will continue to spit and puke coolant until it finds its equalibrium.