Blown Head Gasket 2003 4.0L

[oldmanina2003]

So my daughter-in-law calls me and said her temp gauge hit the red then droppped back to normal during the recent sub zero spell. She drove about 20miles on the xway then exited. It immediatly went back into the red and she drove another couple of miles before pulling over into a gas station. that is where I picked her up to take her on home. I drove the car to my house (better know as dads garage) about a mile down the road. the car had burped out most of the coolant in the reservoir so I toppeed it off. Started it up and brought it up to temp. No heat coming out of climate control. After several minutes I get aother big burp out of the reservoir. Blown head gasket? Did a compression test and found #3 cylinder (back passenger cylinder) had only 140 PSI while all others had 175 to 185 lbs. Also usd a hydrocarbon tester and it tested positive.Thinking about a top end rebuild. How hard is this to do in the vehicle? I understand the rear timing chain removal is a bear. Any stickies to help me out here or am i on my own.

 

[ikuenzi]

I am about to face the same exact thing but I also have a transmission to do on the same vehicle. there Is a writeup that 2000streetrod did on a 2000 model I believe that is very similar to this engine if not exactly the same. I will be posting a ton of pics and material as I get parts in so you can keep an eye on my post in the next week or so good luck man

 

[oldmanina2003]

The fun begins

I have decided it is best to pull the engine. Since it will be adding considerable life to the engine to rebuild the top end it makes sense to replace all the seals too. Not looking forward to this but I have no alternative. Looks like I will be replacing all the timing chain components and buying some special tools too.

 

[Mjdtexan]

Ah, I was hoping to see a bunch of advise on how to do it here. I have the 2005 Explorer 4.0 and I suspect a bad head gasket or a cracked head. I am guessing that it would not be recommended to do just one head. I reckon I will order both heads, head bolts, and a head gasket set to include the exahaust and intake gaskets. I am seeing that some special tools may be required.

Both heads, plus new bolts and the gaset set total $1035 before taxes at AutoZone. Yall remember when AutoZone was called AutoShack? I do.

Let us know how your upper end rebuild goes. I intend on taking lots of pictures of mine.

 

[2000StreetRod]

not necessary to pull cassettes

It is not necessary to pull the cassettes in order to replace the heads. But the camshaft sprockets must be removed from the camshafts so the camshafts must be retimed after the new heads are installed. Unless you intend to keep the vehicle for a long time I suggest pulling the right (passenger) valve cover to determine if the rear cassette is broken before pulling the engine. If it's broken then pull the engine and replace the cassette while replacing/repairing the head. If it's not broken then decide if you just want to replace/repair the head.

 

[oldmanina2003]

Gasket Set Help

OK I am ready to pull the engine out. I have bought a set of reman. heads, Cloyes timing chain and guide set, and OTC Timing kit. I have decided to go over this engine and make sure it will be good for at least another 80K miles when it goes back together. I am working on a tight budget since it is my son's car and he has limited cash. Can anyone point me toward a good source for an upper gasket set with new head bolts? I plan on pulling both heads, replacing the complete timing kit with exception of the balance shaft. I am not going to pull the bottom skirt unless the guides have shattered.

 

[Merc02]

this guy is in California, don't know anything about him, but "headbolt" is in his username.
$35.99. He has 99.7% positive feedback

http://www.ebay.com/itm/110892044216

 

[oldmanina2003]

Bad news!!

Pulled the heads and took them to my machine shop and got a call later in the day that the heads were so warped that they couldn't be machined flat. Will anything go right with this project. So Far:

1. Blown head gasket right side
2. Broken timing chain guide right side
3. Broken balance shaft chain tensioner
4. Warped heads

Ford engineers sure had their heads where the sun doesn't shine on this POS.

 

[2000StreetRod]

remanufactured heads?

In a previous post you stated you had purchased a set of remanufactured heads. Why are you worried about the old warped ones?

Any engine will overheat and possibly warp the heads when the coolant is frozen due to inadequate low temperature protection. The heads and head gaskets are adequate for normal driving. I admit the gaskets and pistons may not hold up to forced induction. In my opinion the only major engine design defficiency for normal driving is the low reliability of the camshaft timing related components.

 

[03explorereb]

In my opinion the only major engine design defficiency for normal driving is the low reliability of the camshaft timing related components.

x2
these engines are notorious for timing related issues. why ford didn't use a keyway for the sprocket or definitive timing marks is beyond me. be wary and ask questions before assuming anything. an assumption can spell catastrophy. tricky indeed.

 

[oldmanina2003]

Fyi

I did buy a set of reman heads just for insurance. I found them on Craigslist for a price I couldn't pass up in case I needed them. I was hoping to sell them for a small profit if the origional heads were usable.

I work for a company that supplies the cleaning equipment to clean major components for engines and transmissions. I have worked in engineering for over 40 years. It never ceases to amaze me how car manufacturers come up with some of their hairbrained ideas. Designing an engine with 3 timing chains, four if you include the balance shaft and then using plastic guides is the epitomy of stupidity. Any chemical engineer with half a brain knows that oils will leach the polymer out of plastic making it brittle. If you have one of these engines and you get more than 100K you should consider yourself lucky. There, now I got it off my chest. Now I can just bite the bullet and get this thing fixed.

It is kind of comical right now at our company. We are working with most off the major auto companies on the 8, 9, and 10 speed transmissions. They are all tripping all over themselves trying to get them to market. Word of warning. Give them a couple of years before you buy one of these. The only proven one on the market is the ZF 8-speed RWD.

 

[2000StreetRod]

Thanks for the caution advice

Recently we began thinking about selling our 2006 Highlander while it still has no problems. I refuse to purchase another front wheel drive vehicle and my wife doesn't like the front on any of the new mid-size SUVs. She said the Grand Cherokee wasn't as bad as the rest and it comes with two wheel rear drive. When I learned it has a new design transmission I said let's wait another year.

Since you are now committed to rebuilding your engine instead of just replacing it, I hope you continue to post your progress. I suspect I'll be trying the same thing in a year or two.

 

[oldmanina2003]

Torque to Yield Bolts

Does anyone know of a source for the timing gear torque to yield bolts. I am sure the local Ford dealer will rob me.

 

[03explorereb]

check ebay. I have bought a couple from there before. I don't recall what the price was but it was significantly cheaper than ford. there were other tty with them if I recall correctly.

 

[2000StreetRod]

which bolts?

The camshaft sprocket retaining bolts can be reused as can the cassette guide positioning bolts. The only camshaft related TTY bolts I'm aware of are the jackshaft front and rear sprocket retaining bolts. I have posted a list of Ford part numbers: SOHC V6 Timing Chain Related PNs
I purchase my parts online from TascaParts.com That saves me two trips to the local dealer (1st to order & prepay, 2nd to pickup) and they are less expensive even after paying shipping costs.

 

[03explorereb]

huh, they didn't look like tty bolts but I could've swore the cam sprocket bolts were tty. believe it or not, during reassembly on a 4.0 I did a while back I had one of those actually snap the bolt head off during torque procedure. I believe it was the passenger side head. that sucked. must have been a factory flaw I guess. makes you wonder though about some engine failures. I have never encountered something like that.

 

[2000StreetRod]

lever arm adapter?

Were you using the special adapter that allows access to the nut with the engine in the vehicle? The torque setting using it is less because of the lever arm advantage.

 

[03explorereb]

no,
forgot to mention the engine was out of the vehicle. I can't remember what the torque value was but it didn't take much. it felt kinda funny when I loosened it. didn't think a thing about it til retiming the engine. whoops!!! I have built close to 40 engines but never had I snapped a bolt due to overtorquing.