4.6L Heads/Engine Replacement??
 

Going to purchase a 1997 4.6L F150 Lariat Supercab 4x4 5sp with 185K miles, that's "blowing white smoke." Does $3000 seem fair? It does to me.

I talked to one engine shop nearby and the owner seemed honest and knowledgable. He said it was likely a cracked head (not a head gasket like the owner thought) and he would replace both heads for $1000. He said the 4.6L block was bullet proof and should still have some miles left in it. After I pushed for a worst-case estimate, he quoted replacing entire engine with 18 month warranted rebuild for $2000-2500. (depending on extras needed, and core shape) I don't remember the company but can find out.

What to do?? This will only be a weekend hunting truck, but the club is an hour away so dependability is important. What are your suggestions? Any companies to stay away from, steer toward? Should I go ahead and replace the clutch too? Anything other options to consider - like a used engine, specific heads, etc...?

Thanks!!
Jason

Looking forward to some replies myself
 

I am ready to replace my wornout 175000 mile 4.6L. I was quoted $2700 for a rebuild regardless of block condition.(less cracks etc.

After it's rebuilt, I would say it would be as dependale as anything. My 4.6 has never let me down, I imagine you'd have to be in some pretty extreme conditions to crack the heads, but the guy is right, the block is bulletproof. As far as the clutch and everything else goes, I wouldn't worry about it unless it is bad. It's all Ford, so it should be good for quite a while.

I think we're getting ahead of ourselves. 3K for a truck w/ almost 200K and a bad head/ gasket/ engine? Tell them for $500 you'll do them a favor and take it off their hands. Think about it: $3K, plus new heads plus labor, and rings and bearings that still have nearly 200K on them. For $5K, you can find a 90s f-150 with a 4.9 (also a bullet proof engine) with half the miles. Then you can go at least another 100K before you see any kind of smoke.
How does the machine shop know it's a cracked head and not a gasket??? How did they pressure test the heads with them still on the truck, which they haven't even seen? Forget this heap, IMO.

I appreciate the reply and you may be right... but if you know of any 97+ ext. cab 4x4 trucks with 100k miles for $5k, give me the phone number! What I've found for $5K is reg cab, 150k+ miles and usually 93 or older (usually 87-91)...

The guy at the shop was giving worst estimates, per my request. He said it could be cracked and with the miles $1K to completely redo would be a safe bet.

For $4-5K still seems like a good deal, anybody else think so?

I would bet money that it is just the head gasket as it is very common and cracked heads are very un-common on these trucks.

No it is not ALL Ford! The Tranny is made by Mazda (5 speed manual)

Personally I would keep looking.

After looking, I bit the bullet... Truck is in great shape other than that little engine thing;). Not perfect, but very well maintained. Everything worked. Every car this guy owns (except the new 250 crew cab bought to replace the '97 F150) has ~200K miles and look/run great.

We did crank the engine - Very briefly. It ran, fairly smooth idle but "rattled." Can't describe the sound any better. He said it was due to antifreeze collecting there over the last few weeks, not fully combusting.

Oil pressure was near the top of the gauge - where it always has been. Oil looked clean on stick, but my eyes aren't a real analysis. Didn't notice any leaks anywhere, no evidence of boil-over, etc... No white smoke this time, but we only let it run for 10-15 seconds. Exhaust smelled sweet and could smell gas in the nearly empty anti-freeze resevoir.

Question is this... Any way it could be the infamous lower manifold gasket?

I will likely have it towed to a shop for diagnosis. Already talking to a couple of local guys. But with the listed symptoms wondering if something like this would be possible to check on my own first?? Still think I'm ok if I need to invest another $2-3K in the old girl, but for a weekend driver (<3k miles a year) want to keep costs low.

Replacement of the engine is inevitable... Am I just kidding myself with 186K miles thinking I can squeeze out another 20-30K? Should I go ahead and start looking for a used engine? Warranty for rebuilt is nice, but my usage is so light, not sure it warrants an additional ~$1K. (Just guessing $3K total for rebuilt and $2K for used)

Thanks again for everyone's insight!

Jason

If it really is the head gasket/head and it gets repaired, I'd say another 100k is left on the engine before it's finally gone, maybe more. I'd say go for it. Even though the tranny is Mazda, Ford owns Mazda, and evidently Ford feels that it's good enough to be in their moneymaker, the F-150. I think it's a fair deal for that truck.

Gas smell in the antifreeze is a sign of a blown head gasket. Your heads may be warped from over heating but it is most likely the gasket. The triton engines came
with "failsafe" cooling which protected the engines from overheating. Pull the heads, you need to anyways to change gasket, and inspect them along with the block surface. If it was me I would pull the engine and rebuild. At the very least I would check the Crank bearings.

If you do pull the engine have a look at the clutch and the slave cylinder. The slaves are prone to leaks and the clutch is a POS.

Regards

Jean Marc Chartier

Thanks for the input!

Have one shop willing to inspect and only replace head gaskets, but considering the high mileage, looking at complete used or reman. engine now... However, would still like to stay under $2K.

Think used engine makes more sense because my weekend usage renders warranty less valuable (will only drive 3-5K miles/ yr).

Anyody have trusted engine sources? (Local scrap yards are high with little/no warranty.)

Clutch seems OK, but tough to say without driving. Will replace while engine is out... Which is best for "typical" driving?

Thanks again,
Jason

If you are just going to put around any OEM spec clutch will do fine. If you plan on pushing the limits like I do then you will need a better than "stock" clutch. Centerforce Duel Friction is one of the best.

JMC