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Discussion Starter · #1 ·
Having coolant level troubles. Only very small puddles at front corner of car ... coolant level very low despite adding ... oil level very high and choc milk shake look ...
Question ... does this engine have a coolant passage in the intake manifold ? Plugs were changed twice and gasket was reused both times when manifold was removed to get at rear plugs ... prob could be gasket leak but i do not know if coolant passes through this manifold or not .

Please help if you can. Thank you
 

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Definitely there's a mix of water and oil. I suggest that you replace the gasket. It is recommended to use new gasket for almost all types of jobs.

I don't know if water is finding its way through the gasket but I suppose you only encountered this problem since you opened it.
 

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Discussion Starter · #3 ·
Definitely there's a mix of water and oil. I suggest that you replace the gasket. It is recommended to use new gasket for almost all types of jobs.

I don't know if water is finding its way through the gasket but I suppose you only encountered this problem since you opened it.
Have not removed manifold yet. Found prob because of checking for reason for coolant level low, no heat, and car over heated once but not since .
Was reading my Haynes manual ... decided to take a look at oil .. is way high on the dip stick plus milky look ... that is when i thought head gasket, or crack , or cylinder crack ..BUT if this manifold has a coolant passage , combined with not changing intake gasket ... the possibilities are high that its just that gasket leaking and not a big repair job .
Not all intakes have coolant passages ... need to determine if this one does .. if so it is worth a try to fix ... i can do it myself .
Cheers dc
 

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2005 6S wagon 5MT
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This sounds like a water pump failure. On the Ford 3.7, the water pump is driven by the timing chain and is under the timing cover. When it fails, it dumps coolant into the oil.

The 3.5 and 3.7 are notorious for this to the point where I believe there is currently a lawsuit involving the Explorers with the 3.5.

Your leak at the front may also point in this direction as the pump has a weep hole that is supposed to evacuate the leaking coolant, but apparently is insufficient.

This video explains better than I can:
 

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2013 Mazda 6i Grand Touring - 2.5L I4 Auto
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I'm not sure if @tango has the same car and I'm not sure if he has done a similar work on his car.
I have the 2.5L engine, actually. I've never done any work with the intake manifold on my car either. But, I did manage to find some information that will be of use to the OP.

As it happens, coolant does run through the intake manifold on the 3.7L. The engine has a two piece manifold arrangement where only the lower part that bolts to the block in the V, Mazda calls an "intake manifold". The upper part that has the throttle body bolted to it is called a "dynamic chamber". Yeah...dig that. Anyway, coolant runs from the pump (10), through the block (11) to the rear (transmission side) of the engine and up into the rear of the intake manifold (9) where it then passes through the thermostat housing (7) and then either back to the block (thermostat closed) or to the radiator (2) (thermostat open). There doesn't seem to be much cooling effect going on at this point, but is simply a passageway for the coolant to get to the thermostat, since the thermostat housing is bolted to the manifold. Here's a diagram:


Font Auto part Automotive exterior Automotive window part Line art


What you remove to get to the rear plugs is the dynamic chamber and not the intake manifold. The dynamic chamber does not have coolant running through it at all.

I hope this helps.
 
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