1999 Dodge 318 head gasket. WWGRM do

So yesterday I found the mystery coolant leak. Head gasket, drivers side. Coolant was running behind the starter and into the front diff skid plate hiding the leak fro view. The leak isn't terrible. About a pint or so every 200 miles. And so far there is no evidence of coolant in the oil or oil in the coolant..

So I have a dilemma. Should I just change the head gasket on this motor or get a long block to swap. Motor has about 150k on the clock and they haven't been easy miles. Lots of towing, hauling, and lately some off road adventures. There is no smoke in the exhaust, but it does tick a little bit when it's cold. Sound goes away once it warms up.

My thought is that I'd hate to go through the trouble of changing the head gaskets just to have a bearing ring, or crank real ho out right afterwards. But I'd also hate to drop 1500 on a long block and have to pull the motor out of a very tall vehicle.

I have no intention of replacing the truck with something new as that is WAY outside my economic comfort zone. How close am I to the end of the road with this 318? WWGRM do?

It's a 318, one of the toughest motors know to exist. Change the head gasket and rock on.

It's an easy motor to do head gaskets on so I'd just do it. Change the intake manifold plenum gasket while you're in there. Other than that, they're solid motors.

For an idea of the scale of this job,I've had the heads off my 360 enough times that it's down to a 1.5 day process working outside And there's much more room to work in the trucks than the space I've got in the Jeep...

Then the next question is what gaskets and bolts? It looks like fel pro and victor reins both have gasket sets. Any experience with these? Are there better? And whose bolt set?

For the head gaskets, either Felpros or the Mopar Performance thin gaskets. For bolts, either a new set of stock ones or a set of ARPs will do the job.

Are the bolts one time use only? I don't know about the 318 specifically, but most older engines had reusable bolts.

They're not torque to yield, so in theory they can be re-used (IIRC, Chrysler's manuals say they can be re-used once before replacement). But IMO, if they've been in an engine for 15+ years, it's not worth the risk considering even the ARP bolts are only $100-ish.

150k on a 318? Unless it's sludged up or something I would put gaskets in it and keep going. Get the Fel-Pro kit with the valve seals and whatnot, bolts if you feel like it. I wouldn't if the factory book says they can be reused, not like you're building a race engine or anything.

If the engine isn't consuming oil, and it still holds good oil pressure, like the others have said, do the head gaskets and go on with life. I would recommend replacing the plenum pan on the intake manifold with a billet replacement from Hughes Engines. The sheetmetal pans like to warp and leak. As for head gaskets and bolts, go with Felpro for both. A set of head bolts is $33 most places. While the heads are off, might as well freshen them with a valve job, fresh springs, and valve seals. 318's will go almost forever with only a little care.

It's an iron V8, there's no reason to start considering a long block. I took a 150k 318 out of a 96 Jeep and slapped it in my wagon pretty much untouched. It still had the crosshatching in the bores when I was swapping oil pans. Fix it and keep chuggin.

Short block should be fine, those 318s are tough. I did a head gasket change on a 92 Dakota, not bad to do. I did get the Fel-Pro bolts and gaskets.

One thing to watch out for, the Magnum heads are notorious for cracking between the valves, especially the middle two cylinders. I have heard between 75-90% of the heads are cracked. Makes sense why there are quite a few new replacement heads available. So something to consider/watch out for.

Yeah, the cracks are definitely something to look for. Usually they don't go through to water, but I'd be hesitant to bolt a set of heads back down knowing they were cracked.

My personal rule is that if the heads need to come off, might as well just rebuild the whole damn thing. That way, the engine goes back in for another 150k miles. If the cylinders aren't bad, I'd just run a quick hone through them and put in new piston rings. You can do this work while the machine shop checks and rebuilds the heads.

In a 318 change the gaskets and drive another 150k. Have you done a timing chain? Usually 100,000 miles is where I've done them and I've had two that crested 400k.

It's the while you are in there things that made me think of the long block possibility. But on further consideration I think I am going to force myself to keep this a simple gasket swap. If I find something scary along the way like cracked heads or scored cylinder walls il can always reconsider. Pulling a short block out would be easier anyway. Thanks for all the advice.

Cylinder wall and ring wear is usually not much of an issue on the Magnum 318 / 360. My 360 still had some crosshatching left and no significant wear ridge at 204k when I had the heads off it and with fresh (not stock) heads with slightly smaller chambers and thin head gaskets (compression bumped from 9.1:1 stock to about 9.7:1 now) it had no problem punching better than stock numbers on a compression test. I had the heads off it at 120k for the first time and the cylinder walls looked almost new at that point.

So the update

I got the head gasket set and set a weekend to get it replaced. Started early Saturday morning so I'd have the whole of Labor Day weekend. It couldn't possibly take more that 3 days right?

All went well ..... accessories, brackets. Exhaust manifold....Until the intake had to come off. First bolt..... SNAP! Not a good omen. But these things happen. I'll be gentle going forward. 2nd one..... Felt iffy there but eventually came out. Kept going and the rest came out easy. Pulled apart the valve train on the bad head side and pulled the head. Messy, but expected.

Soak the broken bolt in penetrant while I clean the mess. Weld a nut on the broken bolt. Put a wrench on it and SNAP! Breaks again. Dang! Was hoping not to have to drill it out, but I guess that's where we are. SNAP! Bit is now stuck in bolt.

Machine shop it is....

2 weeks later I get it back. ( in fairness it was a short first week and I let them put it later in the log since I can only work on this over weekends anyway. Getting it Monday does me no more good than Friday) get it on. Replace the water pump while I'm in there. Flush the oil and coolant out for new. Start it up....

Sounds great. Good oil pressure, but now my temp gauge is not working and the check engine light stays on. Oh well. Back in I go next weekend.

By the way. Does anyone have a picture of the little vacuum thingy on the firewall drivers side by the throttle and a picture of the temperature sender plug with which wires are which for a 99 Durango. The lack of a temp gauge makes me think that is the origin of my issue since the plug fell apart during disassembly. But I am also unsure if the two vacuum hoses on the firewall doodad are right as I didn't label which port they went to and my photos suck!

For the temp gauge, there's just the 1 sender up front on the intake. It feeds the gauge and the ECU, hence the CEL.

In reply to rslifkin:

Does it matter which wire is which on the connector? The female connector came apart when I removed it from the sensor. Not sure if I'm dealing with a polarity issue or contact issue when I snapped the wires back in the connector housing.

As far as I know, there's nothing fancy about the sensor, so it shouldn't matter.

Polarity doesn't matter on that sensor.