Blown Head Gasket and other things

[rhonmorr]

Hello,

I have a '99 Explorer that has over 270,000 miles. I bought it new and love it. Never want to give it up. However, my mechanic has just diagnosed a leaky head gasket that needs to be replaced, and recommends I replace both. Says I have 2. The truck was towed in after smoking and water leaking right out when I poured some in the radiator. My mechanic told me it was, and replaced, a "freeze plug" and also replaced a "timing chain cover", and a "valley pin". I put these in quotes because I don't have a clue. Now, the head gaskets. I had a new transmission put in around 2011 or 2012 or so, and a new radiator in 2014. He says there is a lot of rust, but that the engine is still good and the truck will keep running forever as long as I keep the maintenance up on it. He quoted the head gasket job at about $800. What to do?

 

[1998Exp]

You will get much more useful advice if you let us know which of the three possible engines is in your truck. If you don't know, just post the eighth character of the VIN. It will be a letter.

Hello,
I have a '99 Explorer that has over 270,000 miles.
...
He quoted the head gasket job at about $800. What to do?

 

[rhonmorr]

Oh, thanks. The eighth character is 'X'.

 

[XLTrunner]

Your truck has two heads. What he's telling you is that, as long as he's got the engine stripped down to replace the one side leaky head gasket...you might as well spend a little extra now (rather than much more later should the other one blow out) and get the other done; especially, if you plan on keeping it awhile longer. This is called "MAW" (Might as Well) maintenance.

I don't think $800 for both heads is out of line based on rates around my area. And only you can decide if it's worth continuing to put money into repairs.

 

[rhonmorr]

Yes, that is exactly what he said, that I might as well replace the other. I feel guilty now for even asking about this because I do trust my mechanic. He's been taking care of my truck for about 11 years now and I've never felt like he was overcharging me for anything. It runs good, and only every two to three years some other little thing might go wrong. Aside from that transmission, I've never had to pay more that $200 for any maintenance visit. He even charged me only $700 for the transmission. I only do local driving in the vehicle, and that's really all I need it for now. I would like to keep driving it for at least another five years if I can. He didn't give me a total estimate for all these things, but I doubt if he charges me over $1100. I think it'll be worth the investment for the next 3 to 5 years. Thanks for your input.

 

[chefduane]

It actually sounds like you have found an honest, reputable, and competent mechanic! No offense to the mechanics here on the forum, but they can be sometimes hard to find.

 

[1998Exp]

You have the 4.0L V6 OHV engine (also known as the V6 pushrod). If you put that piece of information in your profile, nobody will bug you again with a question about what type of engine you have. And a couple answers to your terminology questions:
1) "Freeze Plugs" are made of sheet metal, about 1.5" in diameter. They are installed in the block (and sometimes in the heads as well) to close access holes to the water (coolant) jacket. The name comes from the fact that they may pop-up if the coolant freezes. Actually, these access holes are a byproduct of the casting process.
If the coolant is not maintained properly they like to rust and need to be replaced.
2) The timing chain cover is what it says. It sits on the front of the engine, just behind the water pump. Your engine has a chain that drives the camshaft, which needs to rotate at half the speed of the crankshaft. The chain is driven by a small gear on the crankshaft and drives a larger one installed at the end of the camshaft. Because the water pump sits on top of this cover, there are coolant passages through it. Over time this (rather ancient) design may lead to coolant leaks. Sometimes the cover is damaged in the process of resealing (or is warped to begin with) and needs to be replaced.
3) No idea what a "Valley Pin" might be. Anybody?

Oh, thanks. The eighth character is 'X'.

 

[decipha]

in my experiences if you've had a faulty freeze plug then the others aren't too far behind it, not to mention the stock freeze plugs on the 4L engines are thin from the factory

my mom daily drives a 99 explore 4L and the trans lost 3rd about 6 years ago, I programmed the ecu at that time to skip shift it and its been lugging along all these years, 6 months ago 2 freeze plugs started leaking, then 2 weeks ago another, the back ones are not fun to reach with the engine in vehicle

best bet, if you want to keep the vehicle, get the mechanic to yank the engine and rebuild it, it sounds like you have competent and honest mechanic thats damn cheap, if you just re-ring it and bearing it you can probably get a full rebuild done for ~1800 total

 

[ranger7ltr]

3) No idea what a "Valley Pin" might be. Anybody?

Could your mechanic said "Valley Pan"??? I ask because if the intake manifold gasket starts to leak at the front or back ends coolant will pour out of the engine as fast as it gets to the ports in the heads...

I have replaced the intake gasket on my 99 OHV engine a few years back that suddenly started losing coolant... One of the end pieces in the valley pan gasket failed and the lack of sealing caused the coolant to pour out of my engine... Fortunately I was close to home when it happened...