Here is the deal it's an 89 V6 4Runner. I am leaking coolent from what looks like the HG. The reason I am not sure is I have no water in my oil or oil in my water. It has been leaking alot but only on the front of the engine. I first thougt if was the water pump but now I am not sure. The ? is can you blow a HG and not get oil in the water. Any words of support on doing the HG yourself? Thanks for your help. I tried to post some pics but I am computer dumb. Bryan

 

Bryan,

Yes you can blow the HG and not mix oil and water.... check out the threads by Morphine and SilverTruck on this site. There are many others here that have done this also but those two come to mide first...

 

Yes, some HG leaks are internal and some are external. The worse ones for the engine are internal because of the coolant mixing with the oil and getting into the cylinders. An externally blown HG usually doesn't do any damage to the engine unless you leak so much coolant that it over-heats. The 3.0L usually blows internally, but some have blown externally too. The early 3.4L engines had a common problem with externally blown HGs.

 

Thanks for the info. Guess I am doing a HG job any tips or tricks I should know about? I am going to due a search but I seem to remember someone talking obout oversized valves. Is this worth while? If I have them off they will go the the shop. Thanks again Bryan

 

If my heads ever come off again I'll be putting in EB's 1mm OS valves. http://cgi.ebay.com/ebaymotors/ws/eB...968325612&rd=1

 

Hey mt goat would you still put those in if you weren't going to do anything to the bottom end? Will those increase my chances of blowing out my rings?

 

unless you try running some super high compression or your engine is already jacked up, improving the top end isnt going to hurt the bottom end....

 

Yes, I would do it without doing anything to the bottom end as long as the bottom end was still in good shape. I wouldn't put a lot of money in the top end if the bottom end was shot. I think if my bottom end needs rebuilding I'll do a 3.4L swap instead. I may do that anyway, kind of keeping an eye out right now for a good donor.