Ford 4.6 2v serpentine belt failure - how screwed am I?

Last night, the Slamther threw it's serpentine belt about 10km from home due to a faulty tensioner. I ended up limping it home, stopping every couple KM to let it cool down when the temperature gauge got up near 3/4 of the way. The problem is that the serpentine belt drives the water pump, so I was essentially limping a car with an iron block/aluminum head 10km without any coolant circulating through the engine. It's not making any weird noises, there don't appear to be any leaks or smoke, and I never let it actually overheat, so there is a chance the head gaskets and whatnot are fine. What says GRM?

4.6 has fail-safe mode, when it gets hot it alternates cylinder banks in an attempt to keep temps down. You should be good.

I am of the camp of just replacing the belt and run it.

If the head gasket and/or head will leak than it leaks and fails. I don't know of anything that you can do if the damage is already done.

In reply to etifosi:

Thanks! This could very well mean that I need only $45 worth of parts instead of $450 worth of engine and hoist (and transmission, because it would be rude not to do a TR3650 swap if the engine has to come out).

Put a new belt and tensioner on and find out. If it didn't overheat it's probably fine. If the HG went, it was already on it's way.

As a point of reference, my last work van gernaded a pulley at highway speeds and turned the belt to spaghetti. I call the boss and he said to just drive it home because our flatbed driver was not available, and he wasn't paying for a tow if he didn't have to.

I drove it at highway speeds 40 miles back to home (in cool weather). It ran warm, but didn't overheat. I think the air coming through the radiator was spinning the fan, in turn spinning the WP, just a lot slower than normal. It finally konked out on my street from a drained battery.

jimbbski wrote: I am of the camp of just replacing the belt and run it. If the head gasket and/or head will leak than it leaks and fails. I don't know of anything that you can do if the damage is already done.

It's more a question of "do I pull the engine now, or do I wait until something happens in the middle of winter." But, if I swap the tensioner and throw on a new belt and there isn't any smoke or codes, I should be fine.

Replace it and buy an extra to keep with you in the car.

You will be fine. Head gasket issues on the 4.6 are exceedingly rare and it sounds like you had a lot of mechanical sympathy with your plight.

I did a write up some time back of when I had a zero-coolant scenario with my VW (well, due to an air pocket, all coolant was in the radiator, not the engine, further explanation is beyond the scope of this post - the cooling system on longitudinal 5-cylinders was screwy) and I was able to limp the car home by shutting the engine off downhill and coasting at WOT to air-cool the engine from the inside. I did this for something like 30-50km. (For the shockingly high number of Ohio GRMers, I drove from Lodi to the West Park neighborhood of Cleveland)

Head gasket was fine, cylinder head was fine. And these engines were kinda headgaskety when they were common.

I've overheated far more fragile engines than a 4.6 in similar fashion and they have lived to see another day. Replace the belt and tensioner, and drive it.

Nothing is wrong. I did worse to my work van when the tensioner blew up in rush hour traffic. Then i put 4k more miles on it. Then i put the engine in the challenge car and pumped 150 shot of nitrous through it repeatedly.

As everyone has said, you should be fine.

Word of caution here: when my 97 exploader did the same thing (seized idler pulley, nuked serpentine belt). I pulled off quickly and had someone bring me tools and we took his car to vato zone for parts. The pulleys fail so flipping commonly they are stocked there, I thought for sure it'd be a dealer item. Back to the truck, bolt on the pulley. Then try to install the belt, it won't go. I try. And try. And try to get the belt on, literally fighting it for an hour. Back to the 'zone with the too-short belt fuming and ranting. Apologetic clerk pulls another one from the stock, turns out some simpleton had put the wrong belt in the package I needed. It was 4" too short.

Learned a lesson, check the part number on the item, not just the box.

Tensioners and idler pulleys are an EXTREMELY common failure item on everything, they tend to be in-stock items for popular vehicles. Usually the tensioners sieze, but the Mod motors like to eat the bearings so the tensioner pulley tries to bury itself in the timing cover.

Also, the Mod motors have a really, really, REALLY annoyingly difficult tensioner setup. The tensioner is okay, unthreading the belt from it is usually not.

In reply to Knurled:

Oddly enough, I find that the belt threading isn't really annoying. You just have to hook it around the pullies and then just thread the needle. Although it's probably a lot easier on a lowered Crown Vic than, say, an E-series.

patgizz wrote: Nothing is wrong. I did worse to my work van when the tensioner blew up in rush hour traffic. Then i put 4k more miles on it. Then i put the engine in the challenge car and pumped 150 shot of nitrous through it repeatedly.

GRM Level = Supreme Galactic Emperor

My wife drove about 20 miles (Cleveland to Strongsville, since we're using NeOhio distances here) with no serp belt after a pulley grenaded. We put at least 50k on that car before selling it.

With that in mind, maybe change the tensioner and idler pulleys while you're in there.

XLR99 wrote: My wife drove about 20 miles (Cleveland to Strongsville, since we're using NeOhio distances here) with no serp belt after a pulley grenaded. We put at least 50k on that car before selling it.

I used to work in Strongsville and spent my nights near the Gold Coast. Subaru stopped holding water in the radiator, and I was late for work. Bolted the throttle down and hit a new top speed on I-71. Fark it, the car was too rusty for a new radiator and I was late for work. I figure the lack of drag on the water pump impeller was good for the extra 5mph.

That night after work, I put water in it and most of it ran right into the oil pan. Tried cranking the engine and muddy-looking water shot 6 feet through the grille Hell, I didn't really care. I'd just bought my first RX-7...

You never really got it hot if you never let it get past 3/4 on the gauge, carry on.

I know it's too late but when ever I buy a car I replace the belt, pulleys and tensioner and throw the old ones in the trunk. It seems that once you do that they won't ever fail. It is worth the slight lost fuel mileage.

In reply to Knurled:

Mine was less dramatic, but the aftermath sucked. This happened on Christmas Eve, and around the same time as the temps dropped subzero. The pulley mangled it's mounting bracket, which was like $500 from Saab at the time. I found a machine shop (Cardinal Machine - it's been like 18 years, but they still deserve credit) who took pity and had a guy repair it for me on Boxing Day since they were a bit slow. Big tip and a few dozen Christmas cookies for the whole shop.

Here's the culprit. Carved a nice groove into the timing chain cover, too. At least it didn't go through the cover, so now a decently thick sheet steel patch is covering and reinforcing the grooved area with J-B Weld as a bond. All I need to do now is order a new tensioner, patch the end tank, install said tensioner, throw on a new belt, and call it good for now. If only income would stream fast enough to get that done before January (still have cellphone and other minor bills to pay).

That seems to be the failure mode. I wouldn't worry about patching the groove over as long as it didn't actually go through it, I think most Mod motors get this scar sooner or later and none of them have had problems.

Absolutely silly layout.

In reply to Knurled:

Didn't actually go through, but got pretty close . Decided to patch it before water gets in an freezes, expanding and cracking the timing cover.