Urgent. Eeeek! Just replaced Head Gasket and now low compression!

[Ben Lessani]

Hi guys,

This isnt a VW so apologies, its for a 1.1 206 - I drove from Glasgow to Manchester to fix it for my mum, as it needs doing ASAP.

I have just replaced the head gasket on my mums car, i stripped it all down, got it skimmed, and built it back up again. I haven't started the engine itself just yet, but I have run into a problem. I was compression testing the cylinders to see if I've done a good enough job, and they are as follows.

1. 9 Bar
2. 9 Bar
3. 8.7 Bar
4. 8 Bar

It was cylinder 4 that was blown, but the compression is down on all the cylinders now - it used to be 14 bar.

Is this a common side effect of a new head gasket - or I have messed it up. I tightened the head 20 Nm, then 240 Degs, so it should be perfect.

[rubjonny]

could just be your timing is out slightly

[Ben Lessani]

thats what first sprung to mind. i marked off the pulleys before removing them, and lined them back up fine.

the cam gear was removed, but it has a woodruff key - so it can barely go wrong. i lined up the camshaft by locking with a bolt at TDC, then as the crank gear doesnt have any markings on it (official markings i mean), i locked the flywheel at TDC. after locking them both - they still perfectly aligned with my original tip-ex markings.

its showing roughly 10 bar per cylinder now, which is just on the boundary of being acceptable, however, it still isnt running.

the sparks were fouled, so i cleaned them up and refitted them, checked the fueling and thats fine. i turn the engine over and sometimes it catches and will run a little, but then it just sqeaks and stalls.

trouble is, my mum drove it to the point where by the engine wouldnt even idle, it run start, run for about 3 seconds, then squeak and stall. i seem to be having the exact same problem after a skim and new head gasket - so maybe the problem is deeper routed.

im going to try and tow start it to free up the engine - but i have lost hope. looks like it will need to go to a mechanics.

help me out guys!

ps. im in manchester

[rubjonny]

hmm, perhaps it jumped a tooth before you started...

[Ben Lessani]

okay, slightly more progress....after leaving it for a while, i came back to it and started it again, this time, it started, and idled - roughly, and a very strong smell of sulphur (which was also present before the head gasket being done when it originally broke down). so, it idles, wobbles away (maybe firing on 3), and will even rev up with a touch of hesitation. there is a very strong whining noise when revved up (maybe the timing belt tension is too tight?).

i still dont want to drive it just incase, but you may be right about it being a tooth out. i dont have a timing strobe - nor would i know how to attach it seen as though there is no HT leads - as the spark timing is all electronic with the coil and ht leads as one component. it seems like the timing is out a fraction though (Mayb just get a garage to check for me (or i might buy a timing tool)).

also, there is a lot of air being blown out the rocket cover breather - like a continuous stream, quite a high pressure....what could that be?

[Thom89]

Did your mum "cook" the engine,   could  be that you fixed the head gasket, because something else went wrong with the engine, and not the initial problem being the head gasket!  a common problem on 206s is the fan relays next to the fan, get water in them, and stop working, another problem area, is going through water on the road! 206s can gulp water up the air intake!! and bend the valves... could explain your odd C/T readings.. if either of the above, you have to expect the very worst.. hope you get it sorted..
Tom