348 Slow Coolant Leak

O.K. the latest issue to grace my garage floor is a slow coolant leak. I had just completed all of the things I wanted to get done and now I find a nice puddle under the car. Here are the symptoms over the last week for testing and looking for the leak. The leak is slow and amounts to one drip every minute or so. This rate is not effected by the recent hot and cold cycles the engine has been put through and only happens when the engine is cold. The car runs perfectly as far as the cooling is concerned. The heater runs find and I have plenty of heat and water is circulating as far as I can tell. The engine temp runs in the 180-195 range and is steady even when idling for long periods. The fans come on at the same time and go off when the temp goes back down. This leak is not present when the engine is hot or after shut down until the engine reaches room temperature of the unheated garage. The warmer the garage, the slower the leak. As far as I can tell the leak I originally found started during the cars storage. During storage the car was subject to temperatures as low as 15-20 degrees, but had the proper anti-freeze installed. I have recently topped off and bled the system which has had no effect on the rate of drippage.

I cannot find the leak directly even with the car on jacks. It appears to be the front of the engine toward the center under the back of the lowest pulley wheel next to the alternator. The engine is dry so it would have to be under the belt covers somewhere or at the top of the lower accessories. I have checked all of the upper hoses and the hose under the intake and they are all dry and tight. I have also tried to find the leak from under the car without success. Now this leak is new and was not present when the car was put away for storage; however it had only been kept in a heated garage before. I find it hard to believe that the engine parts metal would be subject to that much change do to the temperature of the garage, as to cause a leak.

This is really driving me nuts, I was going to try and have the car ready to register this week. I hope it is not the dreaded water pump. I looked at the paperwork from the major done last June at Ferrari of Washington and the pump does not appear to have been changed however there is a charge for a water pump O-ring or gasket on the sheet. Is it possible to tighten the pump while it's in place?

Oh, one last thing. This leak was a blessing in disguise in a way. When I went under the car to find the leak I found two engine cradle bolts partially backed out, not good. I checked the rest and they seem fine.

Any input would be great. I'm sure there are other places to look up front, but I just can't see. I have atteched the pump drawing for reference.

Thanks,

Mike
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Now were talking. I will check that next! I love this board.

--Mike

 

Yes, middle front. I do not see fluid on the intake or the front top of the motor, but I am going to checkout the hose anyway.

--Mike

 

I did not want to get "We need more of a description if you want our help!" I will look tonight and see whats up. Anyway I just solved the 1/4 5/8 CEL issue with a couple new Bosch O2's so things are looking up!

--Mike

 

I have checked and rechecked all of the top hose connections and not one is leaking, even under pressure. The entire top and top front of the engine is dry and I almost got my han permanently stuck to prove that. Again this morning there was the tell-tail front middle puddle. I do not see any way of actually seeing the leak pressure or not without removing the timing covers and I don't see a way of tightening down the water pump bolts. What are the possibilities of a pump being cracked? This is a real issue as the car had the major done before I owned it and I do not want to pull this motor just yet. How do you guy feel about Barr's Leak or any other type of internal sealer? Can the timing covers be removed and the water pump tightened while the motor is still in the car?

--Mike

 

Yup and cross your fingers. I took today off to find this leak and there is a very small chance I just did and its not the water pump. I was feeling around again up front and I put my hand under the termostat housing and came up with a drop! I check the hose and just under it and it is dry. I just pressurized the system and I am waiting for cool down. I am now betting on the thermostat housing seal or the hose end under pressure while the engine is cold. I hope I am right, it will take a couple hours to find out. This was very hard to find because of the rate of leakage and the fact you have catch it under the right conditions. One of the harder things hindering diagnosis was the evaporation of the coolant on the engine. Please let it be the hose!

--Mike

 

Alright now this is getting weird. After letting the engine cool for 5 hours there was no sign of a leak. Not one drop. I checked the water neck and hose, nothing. I wake up this morning and I have the tell-tale small puddle on the ground again. It was fairly warm out yesterday and I believe this delayed the leak in some way. One other thing, the size of the puddle is getting smaller as the weather gets warmer. When the temp gets low enough it drips, around 40 degrees. What can this be? It is driving me nuts! It does not drip when hot, running or even when cold at idle. It only drips for a few hours when cold enough then stops. Everything in the cooling system is working fine! It is coolant for sure, light green and slightly slick. Could a rubber seal be shrinking during cold temps? Why am I not losing coolant under pressure when cold? If this is a weep hole warning, then why is it not constant? I have never seen this kind of thing before on any car I've ever had.

--Mike

 

Tried that, no difference. I heard from another member that their 355 has the same exact issue as my 348. The dealer told him "that the hoses can contract when very cold. The hose clamps will seem tight when the engine is hot." This would seem to make sense. I don't believe I have a head gasket or water neck seal issue, but the search goes on.

--Mike

 

Hmmm.... Lets hope not. I do think that would have happened and been addressed before the last major, the water pump was not changed last time. Only going on event logic, I would rule that out. I think a Tracerline kit as FandLcars posted, will be the next course of action. I've ordered a borescope as well. This is getting interesting. I am really suprised that I haven't found the source yet. It could very well be the water pump, but I am going to try everything else first .

--Mike