Coolant leak, but where???

[Blu]

I have been spedning a lot of my time with my reatta, fixing it, lately. I had the dreaded E042 code, but thanks to this board, I was able to determine it was a bad and/or dirty connection to the ICM. With that out of the way, I have a coolant leak. I notice a small amount of white smoke coming from under the hood while at stop lights. I checked everything out and found a small crack on the left side of the radiator, I will be replacing it as it has seen better days and seems brittle. This, However, is not the main issue. There is coolant laying in the cradle of the engine, under the intake manifold. I cannot for the life of me see where it is coming from. First, I thought it was the thermostat O-ring. I bought a new thermostat (180 Deg. thanks to suggestions from the board) and O-ring. I have not installed it as of yet becuase this is not where the leak seems to be orginating from. With the engine running for sometime and observing things, I can see a VERY small ammount of collant near the O-ring but it dosent even come over the edge of the ridge. Does anyone have any ideas what could be casing this, where I could look, everything seems dry around the water pump, except where the fluid runs down from the top when it overruns the ridges on the block. There are no leaks around the radiator hoses or where the coolant runs through the throttle body. Could it be a head gasket?? Intake gasket?? My exhust seems foggy but it dosent smell like collant and the oil dosen't look like a milkshake. I could post photos of anything in the engine that might help someone more knowlegable then I, determine the cause of this. Any assistance would be most helpful.

[Guest EDBS0]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> There is coolant laying in the cradle of the engine, under the intake manifold. </div></div>

I had a similar leak and it was the "O" ring problem with expansion and contraction. Others are happy with the 1 bolt design, frankly I think it STINKS!! and always have had a hard time with it. Do a search and you will find more information than you want.

[2seater]

While not common, it is possible the intake manifold is eroded where coolant passage meets the head. Every manifold I have removed showed some signs of galvanic erosion around these passages. The modern silicone o-ring style gaskets do a pretty good sealing but the FSM recommends a sealer in the coolant every time it is changed. Coolant leaks can be a devil to find. Many times they are temperature sensitive and only leak in a narrow temperature range.

[padgett]

The secret to any O-ring, partiluclarly one the slides in is proper surface prep. If the manifold surface is squeaky clean and smooth, it won't leak. If rough and dirty, it will. Bolt is just to hold in place, how tight has nothing to do with sealing. Cleaned properly and with never-seize coating everthing the water neck will slide in and out by hand and not cock more than a little when tightening.

That said if everything looks good there is a small diameter U-shaped steel pipe that enters the throttle body (under the MAF sensor) that is a likely suspect.

[Shelby]

If you are going to replace the Raditor you should give the system a good flush BEFORE and AFTER you do the deed.

Since Antifreeze in now $7.5 - $9 per gallon it is a good time to replace the hoses, Thermostat and water pump.

All these cost about the same as the antifreeze.

Also if you are in need of a AC compressor, It is very easy when with the raditor out.

Get out your check book.

[Guest F14CRAZY]

Add a 180 degree thermostat, the Prestone garden hose flush kit, some Valvoline flush stuff that the Explorer dudes say is really good, and a bottle of Water Wetter