Expert: Roland Finston - 11/5/2009

Question
Hello, thank you for answering my question.  I have 2 problems with my car (04' 6cyl 2.7L).  1.  sludge in oil and  2. antifreeze leak.  Okay, so the leak (a slow leak) is coming from the "water outlet housing" is that easy to repair? if so what parts are needed?  Sludge in oil - the oil has been changed twice in last 2 days noticed small amount of sludge at bottom of dip stick last night. Car is thinking about running hot but doesn't quite get there, gets to the halfway mark, however; I have only driven it approximately 3 miles in the last 2 days.  What is this sludge and can I get it out? if so how?

Thank you very much for your help

Answer
Hi Sandra,
The leak at the water outlet housing may be simply a not fully closed 'bleed valve' which is located on the top of that housing and is only opened in order to bleed air from the system when refilling it. Perhaps simply tightening the bleed valve will stop the leak. It is also possible that there is a leak at one of the three hoses attached at the housing which requires tightening. So you would want to observe the location of the leak and then act. If the housing is leaking around where it is attached to the block, then the upper intake manifold may have to be removed to put a new gasket on it, along with the upper crossmember (above the radiator) if tightening the bolts that attach it to the block will not stop the leak.  
On the sludge in the oil, it might be the pcv valve or its hoses are the problem and that is an easy fix. That valve is responsible for recycling water vapor in the oil/crankcase to the intake manifold so as to prevent moisture build-up in the engine. It also may be, however, an cooling system leak of coolant into the engine oil due to a leaking head gasket. That would be a big repair if true. Do you see excessive white smoke from the exhaust pipe when first starting the car from cold? If so, that may be a symptom of such a leak. Also, do you hear internal bubbling sounds in the first few minutes after start up coming from the upper area of the engine which would be a sign of exhaust gas getting into the cooling system. A radiator shop has a tester that can be put in place of the pressure cap on the refill bottle of the cooling system which can detect exhaust gas in the cooling system which would be another sign of the head gasket leak possibility. But first check out the pcv valve for replacement (it is very inexpensive) and verify that its connecting houses are air-tight and not cracked.
If you send a follow-up question let me know how much coolant you are having to add to the system per what miles driven so I have some idea of the rate of loss. It is also normal to have a slight 'weep' of coolant from a hole next to the thermostat housing, so don't be confused by that possibility. If the hole get blocked, then there is a second weep outlet from the water pump that causes a loss of coolant from the rear of the engine between the two cylinder banks. So if you have leakage there try to insert a stiff wire in the front weep hole to clean it out.
Roland