Crank shaft oil seal?

Crank shaft oil seal, what else could it be,
200tdi recently had cambelt done by specialist, wasn't leaking before.
Would you change this when doing a cambelt, Probably not I guess?
Bit of reading suggests it could be 1 of 4 things.
1. crank seal
2. cam seal
3. belt idler stud hole
4. belt idler bolt hole

Could also be the front seal on the injection pump, and it's dumping diesel into the timing chest and it's not engine oil at all.

The crank seal is a pain for a lot of people to do, so, it's a "if it ain't broke" item. It's not hard to do at all really but it requires more thought then brawn (needs to be pressed in square rather than brutalized)

Re pressing in square - you can use the crank bolt itself with a suitable drift / spacer (eg an old crank sprocket) to push the seal in evenly. You just tighten the crank bolt whilst the engine is in gear etc and it goes in.

Took a paid garage 3 attempts to do my friends 300. I assume they were not using the above method.

Edit - my experience is from the 300, but it's all going to be, more or less, the same. Esp the injection pump front seal failing as they're, essentially, the same.

julianf said:

Could also be the front seal on the injection pump, and it's dumping diesel into the timing chest and it's not engine oil at all.

The crank seal is a pain for a lot of people to do, so, it's a "if it ain't broke" item. It's not hard to do at all really but it requires more thought then brawn (needs to be pressed in square rather than brutalized)

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Seeing the injection pump is new I would like to think it's not diesel.
Thanks for tip with regards to the crankshaft seal.
What did you use to pull off the crankshaft belt pulley?

The cheap timing kits off ebay have all you will need, puller etc, but you will need some long m5 bolts to pull off the crankshaft cambelt drive gear, cannot tell you exact length as my tools are 20 miles away.

lynall said:

The cheap timing kits off ebay have all you will need, puller etc, but you will need some long m5 bolts to pull off the crankshaft cambelt drive gear, cannot tell you exact length as my tools are 20 miles away.

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Aha, good show, so I could use the same kit. One less tool to buy then.

Anaconda said:

Seeing the injection pump is new I would like to think it's not diesel.
Thanks for tip with regards to the crankshaft seal.
What did you use to pull off the crankshaft belt pulley?

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As above, that red box kit thing.

The box has pins for the timing also, but I wouldn't try using the crank nut to press in the seal with the flywheel pin in place, as I reckon even with it in gear etc you would get some rotation on the flywheel and the little spring loaded pin would get damaged.

Id probably time it up using the pins (remember the crank goes round twice for each rotation of the injection pump) and then take out the flywheel pin whilst you're taking off the sprocket / seal etc.

Remember you can't just spin it over happily unless you take the rocker assembly off. Which is easy enough but just another thing, and you probably don't need to, so long as you're not getting any real engine rotation.

When you are good to put the belt back on, put the pin back in at that point to make sure it's spot on again, rather than having it in the whole time.


The only other bits you need (again, my experience is from the 300) is a low torque torque wrench (one of those needle things) and some way of locking the engine when you do the crank nut back up at the end. It does need to be crazy tight otherwise they loosen off and the chatter stuffs the woodruff key (etc).

You can get locking things for about £60 that wedge against the chassis rails. Or find someone local who will lend you one.

Or think "it'll be fine" and not do it up tight enough because it's near impossible to do without the locking tool.


Mark the job with tipex etc when you're doing it up as you (or at least I) always loose track of what 90 degrees actually looks like when you're under a car (it could even be 180 - can't remember)

It just so happens I bought a crank holding tool the other day.
Going to give it a jolly good clean incase it's general leaks, stick a wading plug in and drive it around a bit and see if anything comes out.

Anaconda said:

Crank shaft oil seal, what else could it be,
200tdi recently had cambelt done by specialist, wasn't leaking before.

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Not sure there is much that would cause a leak there when doing a timing belt change.
Check usual places like cam cover for signs of leak and anything else in the area.
If it is the crank seal it won't be the first but if you do replace the seal its important to use the right one.
Now there is probably a thread somewhere with all the correct advice but from my memory I first used the seal with a plastic skirt type seal and that failed so I was directed to use the all rubber version that looks like a seal should. That worked and was still fine when I sold the vehicle. Simple enough job to swap once you get to it.

Bantam1 said:

Not sure there is much that would cause a leak there when doing a timing belt change.
Check usual places like cam cover for signs of leak and anything else in the area.
If it is the crank seal it won't be the first but if you do replace the seal its important to use the right one.
Now there is probably a thread somewhere with all the correct advice but from my memory I first used the seal with a plastic skirt type seal and that failed so I was directed to use the all rubber version that looks like a seal should. That worked and was still fine when I sold the vehicle. Simple enough job to swap once you get to it.

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If I do end up changing the seal I will fit genuine if you can still buy them.

Corteco seals are decent.

Garter spring side of the crank seal goes to the oil, timing cover seal garter spring goes to the outside air.