coolant getting into valve cover?

[dford]

I have noticed that the coolant level has been dropping and there is a thick milky goo inside the filler neck and oil filler cap. Dipstick looks to have clean oil. No apparent external leaks and no smoke from tailpipe. I'm guessing head gasket or cracked head or block. There has been no overheating and engine runs smoothly. Is it possible that there may be a vacuum leak sucking coolant from a preheat device et al at the intake manifold? Currently car is my son's transport to and from high school. It's been cold recently and is only used short distances. Amount of goo seems excessive for simple condensation. Has anyone experienced this on their 4.0L? It's an 03 and mileage is 155k. Crossing my fingers for an easy fix.....

 

[CobraGT40]

This exact thing happened to my 1987 Grand Prix 305c.i.
Never really found out what the issue was... I bought it with 34,000 miles and traded it in years later with 220,000 miles. The milky goo was always present inside the oil filler cap, but never seemed to effect anything. I would drive it 1000 mile round trip every 2-3 months and never had an issue.

 

[jd4242]

Check the lower intake manifold bolts..is oil getting into the radiator?

 

[dford]

No oil in the cooling system that I can detect. I did notice, upon closer inspection, that there is a small external coolant leak at the rear of the thermostat mounting block. Coolant is being blown back between the heads by the fan and evaporating before dripping on to the ground. I can see some crusty residue back in there. Not sure if it is somehow getting into the crankcase ventilation to cause the heavy goo inside the oil filler neck.

 

[jd4242]

No oil in the cooling system that I can detect. I did notice, upon closer inspection, that there is a small external coolant leak at the rear of the thermostat mounting block. Coolant is being blown back between the heads by the fan and evaporating before dripping on to the ground. I can see some crusty residue back in there. Not sure if it is somehow getting into the crankcase ventilation to cause the heavy goo inside the oil filler neck.

The thermostat mounts to the lower intake.sure its not where the lower intake mounts to the heads/block.if it was the thermostat housing leaking only you would not be getting it inside the motor

 

[D Hook]

Can you post up a pic of the filler neck where the goo is? It could be a normal amount, especially this time of the year and short trips that don't give the motor time to burn off the extra condensation.

 

[Dsrtdweller]

I hate to tell you but it is probably a blown head gasket? I had the same thing happen on my 69 Monte Carlo water in the oil due to a blown head gasket . Don't drive it ... you'll have to drain the oil, remove the oil pan and clean it out really well,then remove the gasket and remove the head and clean the old gasket off and dry it off. Then put some "Heet " in the gas tank to remove the excess moisture that might be in there also. If you drive it you will BLOW the engine! Dsrtdweller

 

[thepotroast]

It's your intake manifold. This is a common problem. There is a thread about it here:

http://www.explorerforum.com/forums/showthread.php?t=378656&highlight=crack+intake

If you search "cracked intake" in the 02-05 forum, you will see a lot of topics about it. Also some YouTube vids explain how to swap it out. It's actually not overly expensive to do yourself.

 

[dford]

I checked the link you sent. Thanks. This could also be the reason for check engine light and other issues I've had. One question though, the threads I read were dealing with the 4.6. Is it the same for my 4.0?

 

[jd4242]

I checked the link you sent. Thanks. This could also be the reason for check engine light and other issues I've had. One question though, the threads I read were dealing with the 4.6. Is it the same for my 4.0?

Nope ....

 

[dford]

thanks for clearing that up--
but I was hoping that was it--looked like replacing an intake on the 4.0 would have been a fairly easy DIY

 

[Dsrtdweller]

I'm sorry but, the pot roast is right ...it is your intake manifold gasket that needs to be changed out not the head gasket as i said before. I would at least ask around for second opinion bit pretty sure thats gonna be it. Dsrtdweller

 

[jd4242]

I'm sorry but, the pot roast is right ...it is your intake manifold gasket that needs to be changed out not the head gasket as i said before. I would at least ask around for second opinion bit pretty sure thats gonna be it. Dsrtdweller

The 4.0 does not have a ""cracked lim" problem like the 4.6 totally different motors...but it does have a problem with the bolts coming loose on the lower intake, why it has been suggested to try tightening them up first, sometimes that will stop a 4.0 lim leak....rarely is it the head gasket for this year, normally its the LIM or cracked head.or some other problem that's not visible