Head gasket.......... 98 Cobra

[JBeezy53]

So who's done a head swap or Head Gasket on a DOHC 4.6? My 98 Cobra gonna need the head gaskets done as the driver's side looks to be leaking coolant into a cylinder ot 2.

I can take my 5.0s apart blind folded, rebuild them and put them back together no problem. But I've only done one P.I. swap on a 4.6 but have never torn into a DOHC motor. On the 98 Cobra it looks like a real tight fit by the master cylinder and also a pain to get to the header bolts.

So my questions are how much of a hassle will it be? Can I even do the head gaskets with the motor in the car? Also if I have to pull the motor will it come out through the top of will I have to drop the suspension and take it out the bottom? It looks like a pain just to take a valve cover off the driver's side.

Thanks, Johnnie

 

[wmburns]

The Ford service manual doesn't even have a section for in vehicle repair of cylinder heads(SOHC yes/DOHC no). Considering the front timing cover, timing chains, oil pan, exhaust manifold, intake manifold all have to be removed. I think in car repair would be very rough on a SOHC. It may not be possible on a DOHC for the other reasons mentioned.

Consider what would happen if it turned out to be a bigger problem than a head gasket. Then the whole motor would have to come out anyway.

IMO, consider taking the engine out and working on a stand.

The motor can come out from above or below. From above you have the choice of engine alone or engine/transmission together. I did my SOHC separately with a crane and stands in my driveway.

Ford makes special lifting brackets that bolt to each corner of the engine (bosses drilled into the heads). They are very $$. I attempted to fab my own using lifting eyes from Eastwood. They looked nice but were not nearly long enough. In order to work, the eyes need to get well above the valve covers or it will interfere with the AC hard lines. As they get longer, they have to get stronger. Otherwise they will bend in and crush the valve covers. Even as short as they were, blocks of wood had to be used to protect the valve covers.

I had to ditch the home made lifting brackets and go with straps under/around the oil pan. Not pretty but it worked. Obviously, I would have been in trouble doing the engine and transmission together.

Optionally, the intake manifold and alternator can be removed. With the transmission/bell housing bolts removed, chains can be attached to the front/back webbing in the block valley. This method has its drawbacks because it is much easier to dress and work on the stand.

Doing the engine and transmission separately probably the biggest hassle is removing the starter. The top bolt is very difficult to remove. What I found works is a long extension combined with a 13MM flex socket. The extension has to be long enough to access the bolt going through the K-member. A little tape around the joint will keep it from flexing too much.

I expect someday to do another engine install. Maybe I am too ridged in my thinking. If someone out there has an inexpensive solution to the Ford modular lifting brackets I would love to hear it. Something that is strong enough to hold an engine/transmission combination and still be able to safely tilt enough to allow the combination to go in through the top.

Hope this helps. Good luck.

 

[JBeezy53]

I figured it will be rough. I was hoping someone would chime in and say it was a pain but I've done it successfully.

 

[ninjastang125]

I have tried and failed and ended up pulling the whole motor out.