I got a crack in the plastic part of my radiator and my car overheated. Not for long but it doesn't take long. I haven't done a leakdown test yet but I suspect a leaky head gasket.

Has anyone here done the heads without pulling the engine, like the manual says to do? Any pointers? Anything else to do while in there? Get my heads rebuilt or do a swap? I've had bad luck before with head swaps on other vehicles. I have 185K miles on the engine but it has been well maintained and was working fine before the boil-over.

There is a special tool for the camshafts for setting the timing. Does anyone know another way?

Thanks.

The Mark has four cams in the heads, if the heads are not straight the cams will have to be bent to match the heads. In other words the heads are very hard to rebuild.

A pair of good used heads cost almost as much as a used engine, adding in the cost of gaskets, head bolts, etc. used heads will cost more then an engine. If your engine was cooked enough to blow a head gasket I would not trust it enough to mess with new head gaskets.

I'm not even sure there is a head gasket leak. I loose water very slowly. It may be my reservoir cap got damaged and it's not holding the right pressure. There may be a small leak I can't see.
There is a hot process for flattening the heads without lapping them, only a final surfacing. The cam journals can be line bored. The tool for aligning the cams is more than all the gaskets, bolts, etc. combined.
A long block would be a lot more labor and an unknown piece of metal. I do have 185K miles and want to keep the car but things are getting harder to find in good quality. The 4.6 Modular DOHC engine is still pretty common though, so there should be no problem with that.

"if the heads are not straight the cams will have to be bent to match the heads"

What absolute nonsense!

>"if the heads are not straight the cams will have to be
>bent to match the heads"
>
>What absolute nonsense!

I thought he meant something other than what he wrote but there is no way I could make sense of it. The heads could not generate enough force to bend the camshafts without something else very bad also happening. The camshaft bearings could get worn or something, maybe. I don't think my heads are that warped. They may be in spec to be lapped.
I may be able to make an alignment tool using some bar stock aluminum. It's basically a clamp for both the camshafts that holds them in position while you put the chain on.
The only problem I see is that there is not enough room to get the head bolts out close to the firewall. I read once that you can hold the bolts up with a section of hose slit down the side and then move the head forward enough to get it out. Just getting the cam cover off is a hassle. Maybe I can loosen the subframe and raise the rest of the car a little to get more clearance.
My next step is going to be injecting air pressure through the spark plug holes to see if it leaks into the water jacket. Then I'll make a more informed decision.

Edit: I just checked Rockauto and heads are $750 each with $125 core. With camshafts and followers. That seems more than reasonable to me. I think I could get another 100K out of my engine with a little more rebuild, like timing chains & gears, water pump, oil pump, etc.

>"if the heads are not straight the cams will have to be
>bent to match the heads"
>
>What absolute nonsense!

Well, yes it is nonsense. That is the point.

The whole idea of rebuilding warped heads for an overhead cam engine is nonsense, unless you want to spend big bucks.

By the way, Marshall's Auto Parts, http://www.marshallsautoparts.com/ lists heads for $50 each with warranty. I have no connection with them, they are just the result of a random search.

This yard lists a low mileage engine for $300, http://www.a1autosalvage-ar.com/. Another random search.

I don't think there's a leak in my head gasket anyway. I have been having trouble getting all the air out of my system after replacing the radiator. The coolant level hasn't dropped for two days now.

If I got a used engine I would totally rebuild it before putting it in my own car. I really like my Mark VIII and don't want to be putting engines in and out of it very often. Same with used heads, if they're out, rebuild them.

Ok and now for useful information.....
jack your car up in the front and put o n jack stands as high as safely possible. open crossover coolant tube and screw in a funnel, plastic ones screw right in. fill funnel with coolant or water. start engine and turn on heater full blast. let idle for up to 2 hours until all air bubbles come out while keeping funnel full. yes i said 2 hours, it may take that long to "burp" the engine. while engine is still running slightly open coolant overflow tank and suck coolant from funnel until only a small amount is still in funnel then close tank. remove funnel, a slight spill will occur. replace plug in crossover tube then turn engine off. your all done problem fixed. remove jack stands and enjoy.

I can park it facing uphill quite a bit. If I idle too long with the cooling system open the coolant will start to boil off. It is supposed to be under pressure. I think my new radiator is a POS. It probably hasn't got the same flow through it as the stock one. I may JB Weld the old one and put it back on as a test. My temp gauge goes up when I am going uphill in second gear, no other time, like idling in hot traffic. That makes me think the trans is adding more heat than the radiator can handle. I have a trans cooler I've been putting off installing. That may help but I still think the new radiator is a POS.

Try to see if the cross tubes are the same size from new radiator to old radiator. If new radiator (fins) are smaller then that would be a radiator problem. That is a problem with some of these "China" parts coming from places unknown. They are not the same capacity as the factory original.
On a second note, just finished putting head gasket on passenger side head. Three days work 9-7 every day. Two people required to install rocker arms. Four of the lower head bolts have to go in with the head, keep them flush with the bottom of the cylinder and zip tie two each together at the top under the hex head to hold them in place while moving head on block, then cut zip ties. Then your bolts are in place. Do not reuse old head bolts they will break. Roughly takes the same amount of time to change the motor out the top (done that too).
If your system is losing water over night keep an eye on your water pump. As the system is cooling off it will tend to seep. Seen this before on other cars.

>Three days work 9-7 every day. Two people required to install rocker arms.

R & R the rocker arms is a one man job.

See the vid:

http://www.youtube.com/watch?v=mbqKWzhpsHQ&feature=results_video&playnext=1&list=PLF4CAFD68DC23034B

MOD aka "another Craig"
Mark of Distinction
1993 Light Mocha

The cross tubes seem to be the same size. The radiator is from Canada. The difference looks like they used less dense fin louvers. Less metal to draw the heat from the tubes to the airflow. Less aluminum = cheaper. I would say the used two thirds the amount of louver material. I was going to plumb my trans cooler in with copper tubing but I need 5/16 to 3/8 adapters. Why does even a simple plumbing job always require at least three trips to the hardware store?

OK! Not fixed yet but I caught it in the act. The connector to the fan motor is bad. Sometimes it only goes to low speed, sometimes nothing. I move the wires and I can get it to change speeds or cut out completely. When it cools off I will take a closer look at it.

>OK! Not fixed yet but I caught it in the act. The connector
>to the fan motor is bad. Sometimes it only goes to low speed,
>sometimes nothing. I move the wires and I can get it to change
>speeds or cut out completely. When it cools off I will take a
>closer look at it.


Not sure what year your Mark is. This is for '93-'96. I assume '97-'98 is the same.


There are three wires inside your fan connector. The fan is a two-speed fan and gets its signals from the VRCM. There is one blue wire in the connector. This is your hot wire. This wire splits into two wires feeding into the VRCM connection. Each connection in the VRCM feeds a certain amount of voltage into the fan connector and controls if your fan spins at slow speed or high speed.

There is one black wire in the center of the fan connector. It is a dead wire that terminates to somewhere/nowhere inside the wiring harness. I suppose this is a universal Ford connector and this dead wire just keeps moisture out.

The outside blackwire is your ground.

Be careful when unsnapping the connector from the fan. They will break.

MOD aka "another Craig"
Mark of Distinction
1993 Light Mocha

Thanks, another Craig.
The connector is burnt looking, melted and black. I'm going to replace the motor and connector. Guess I will do the thermostat and water pump too, since they are both original with 14 years and 185k miles. Can't hurt. I have the trans cooler to add, too, when I get the time.