ford mondeo valve seals

[goalie]

need to change the valve oil seals on 1.8 2001 mondeo,can this be done without taking off the head

[Garybee]

Yep, either by using compressed air to keep the valves seated or by feeding string into the cylinder then carefully raising to TDC. You can then use a valve spring compressor that bolts to the head.

[Pumaracing]

No. With the valves still in place it's pretty much impossible to get at the old stem seals on 16v engines given they're buried at the bottom of a lifter bore with the valve stem blocking that anyway.

It's hard enough getting old seals off the guides even when the head's stripped on the workbench and you have proper stem seal pliers. I usually burn them off if they refuse to pull off.

You can do seals in situ on engines like the CVH or Pinto where you can get at the seals from the side with a screwdriver but not on OHC engines with flat tappets and lifter bores. Maybe with some fancy special tool that fitted over the valve stem but I've never seen anything like that.

Zetec stem seals tend to last forever though so why do you think yours need changing?

[Pigeon]

Pumaracing said:

Maybe with some fancy special tool that fitted over the valve stem but I've never seen anything like that.

Should be quite easy to make.

Long thin piece of thickish steel strip, put two 90 degree bends in it either side of the middle to make a tall narrow flat-bottomed U shape, wider than the valve guide but narrow enough to fit neatly down some piece of scrap tube (bit of central heating pipe maybe). Drill a hole fractionally larger than the OD of the valve guide in the middle of the bottom of the U. Cut it in half transversely across the hole.

Remove the valve spring, put the two halves down the hole, hook them under the bottom of the seal, slide the tube over the whole thing to hold it together, grab the free ends of the two halves with some mole grips and pull.

I reckon that ought to work unless the valve springs are of an unfeasibly small diameter

[Pumaracing]

Still won't help you much on a Zetec cylinder head. The stem seals are like the later CVH ones with a shim steel valve spring seat built in to the rubber top part. There's nothing to hook under. The way to get them off is jam a tight fitting tube or socket over the top part and rock it until they click loose but you can't rock anything much with the valve stem in the way.

Might be worth asking a Ford main dealer if they have any special tools to allow in-situ changing but otherwise I'd say it's a head off job.

[Garybee]

Would say it's most likely to be a Duratec if it's an '01, not a Zetec.

In case it is a Duratec and you have an engine that's burning a lot of oil. These engines seem to have a lot of problems with their piston rings. The oil control rings can become ineffective at relatively low mileages.

[goalie]

it is a duratec engine.took out the plugs.oil in 2 of them but compression test read 145 psi on all 4 cylenders