I have a leak and I need some help diagnosing it.

A little background : The truck is a F150 XLT Supercab (4.6L V8, automatic) with 190k miles on it. Well maintained and garage kept.

Last year, the heater quit working. Not a big deal, since I live in south Florida and rarely (if ever) use it.

About a month ago, I noticed water leaking out on the passenger side towards the rear of the block. There is no leaking inside the cab or smell. After doing a lot of Google searching, I figured the heater core was shot and/or a heat hose was shot.

The radiator looks fine and there are not obvious bad hoses - everything looks OK the way it should.

I found the source of the leak. It's on top of the block under the bolt in the photos. There is a metal elbow(?) here that leads to a metal line which then goes into a hose which goes back into the firewall (and presumably the heater core).

There is no water in the oil, so I am hoping this is not a cracked head or something major like that. But there does appear to be a gap below the bolt where the water is leaking out, which then flows back along the side of the block and drips down on the rear passenger side.

The truck seems to run fine as long as I keep an eye on the water level, but this needs to be fixed. What am I looking at here? And, if I take this to a mechanic shop, what is a ballpark figure in dollars that I am looking at to get it fixed?

I have basic mechanic skills - can change my own oil, swap out easy parts, etc, but I think this might be above my pay grade.

Any help is greatly appreciated.

FWIW - I don't need the heater. I am more than happy to cut my losses and just bypass the heater core.

Thanks!

MikeG

 

You are looking at one of two things. There's a hose that passes underneath the intake manifold. At around the age/miles of your truck it's pretty common for that to start leaking. If the hose is in fact leaking, you will have to remove the entire intake manifold to get to it.

If not that it could be the intake manifold itself, same thing with the age/mileage of these trucks. I just did mine at 200k. The gaskets fail and leave you with a leak.

Find out for sure where it's leaking from first. If it is with one of the issues I mentioned, replace both parts and be done with it. Be sure to watch your coolant temp. With a leak in the system like that you could start having air pockets which will cause the truck to overheat. If you overheat one of these engines you will likely be doing head gaskets and maybe even head replacements.

 

Thanks Drillrig. That makes sense. I had not considered the intake manifold gasket. This does look/act like that. It did run hot on me once. Is there any way I can tell if the head gaskets or head is damaged? I'm not seeing the dreaded water in the oil, so I am assuming that is a good sign? Many years ago, I had an old Monte Carlo that had a cracked head and it started running like crap and had water in the oil.

Thanks for the input.

 

Mine got hot as well when I had the leak but didn't get into the red zone. That's usually when you will have problems. I've been keeping an eye on it and so far mines been ok. Untill you get it fixed, and even after, keep an eye on that temp guage.

If it ends up being the intake gaskets, make for sure you get that hose replaced while your in there. It would also be the perfect time to do spark plugs and injector o-rings. Also can get a rebuild kit for your coil on plugs (just springs and boots). All those little things can help prevent you from working on the same thing twice in the long run.

 

It did get into the red zone once, but thankfully I was almost home when it happened and I drove for less than a mile when it hit red and then I shut it off. I hope I dodged a bullet there. I replaced the coil packs about 30,000 miles ago. That was my last sizeable repair job. A couple of them were a pain to reach and I had a shade-tree mechanic help me with those. I don't have access to that same mechanic friend any more (he moved away). so I am on my own with this one. My budget is somewhat limited, so I am hesitant to take it to a shop where the labor charges will kill me. I could probably afford upwards to $900 - $1000 on repairs, but I'd hate to do that. Where is good ole Dad when you need him? We never paid for repairs when I was a kid because my Dad always fixed the family cars. Now I am Dad and I can't fix crap. LOL.

 

Lol! I used to enjoy working on things. Nowadays I guess I'm just lazy. The intake is a somewhat tedious job that must be done right or it will start leaking again. For that I chose to have a shop do it. I paid 250 for a new replacement intake and 400 for labor. That includes injector orings, and that little hose underneath. Oh, and some piece of mind that if it failed the repair shop would have to take care of it.

Looks like you have the metal intake, mine was the plastic one. I think you may be able to get away with just replacing the gaskets, but that does not make the job any easier, just less expensive. The going rate is between 4-5 hours for this job, plus parts you should be under 650-700 for a shop to do it. Just make sure they have a good reputation and honor their work.

 

And ONLY use Motorcraft gaskets. You will have to buy them from the dealer. Don't get cheap here, anything else has a high probability of leaking.

 

Roger on the Motorcraft gaskets. Learned that the hard way with the ignition coils. Replaced two of them with some cheapie brand and they lasted about 15000 miles before they went bad again. Finally broke down and replaced them all with a better brand.

That's also why I change my own oil. No bulk grade oil or cheap filters going in this truck.

Just wished I had paid attention when my Dad was cursing up a storm and fixing our cars. But I was young, dumb, and too busy running the streets to learn a useful trade from an expert willing to teach me for free.

 

An update :

I took the truck to a mechanic shop owned by a friend of the family. I thought I was looking at a bad intake manifold gasket, so I was prepared for the worst. Instead, it was just a leaking heater core. The spot on top of the manifold that I saw was just an accumulation of junk and grease, according to the mechanic. They bypassed the heater core and now there is no leak. Cost, just less than $100 for labor. Had I known, I would have bypassed it myself, but I am happy to have it fixed just the same.

 

That's what made it an easy fix.