Rover 45 - No compression in 1 cylinder

halfordartistry

New member
Points
26
From
england sevenoaks
Car
rover 45
I have just changed the head gasket on my 2002 Rover 45 1.6 litre engine.

I now have no compression on cylinder 3, all others are within spec.

Can anyone advise how to diagnose fault as I understand it could be a number of sources i.e. valves, piston, rings or liners.
 

old-git

Moderator
Points
617
From
Essex
Car
Elan & Robin Hood
if you have flat topped pistons, pour a little oil down the spark plug hole and redo the test. If the compression rises near to normal, then the rings are the problem (oil will temporarally seal the rings). If there is no improvement, it is likely to be the valve(s) not sealing properly on their seats .

This is assuming, of course, that the head and block are flat, the head gasket isn't damaged and the flow of air into the cylinder isn't restricted or leaking away before it gets into the cylinder.
 

SLEEPER

Pro Tuner
Points
542
As above but a question

Why did you change the head gasket ? ............

presumably there was a problem -maybe you have not solved it.

If you mistook a bent valve , dodgy rings or a cracked head for a head gasket problem it will still be there if all you do is change the gasket

And if there wasnt a problem before and is now looks like its not been assembled correctly (head bolts not done up right is always a good bet)
 

halfordartistry

New member
Points
26
From
england sevenoaks
Car
rover 45
Hi all
Thanks for comments, will try the test on the rings, but thought there would be some compression even if rings worn.
Sleeper - Head Gasket definitely gone, lots of water in oil and oil in water, masses of steam etc. Gasket blew between pots 1 & 2 by the look of it so did not fully check condition of valves for pot 3. Checked faces of head and block, look ok. Also inspected liners for cracks and condition of piston, appear good. Repacement of gasket seems to have cured the blown gasket problem. The compression problem may have been there before the gasket blew as the engine was a little sluggish but I had a diagnostic test just over a year ago and the garage said it was a misfire in pot 1 due to the head gasket leaking.
 

halfordartistry

New member
Points
26
From
england sevenoaks
Car
rover 45
Hi all
Thanks for comments, will try the test on the rings, but thought there would be some compression even if rings worn.
Sleeper - Head Gasket definitely gone, lots of water in oil and oil in water, masses of steam etc. Gasket blew between pots 1 & 2 by the look of it so did not fully check condition of valves for pot 3. Checked faces of head and block, look ok. Also inspected liners for cracks and condition of piston, appear good. Repacement of gasket seems to have cured the blown gasket problem. The compression problem may have been there before the gasket blew as the engine was a little sluggish but I had a diagnostic test just over a year ago and the garage said it was a misfire in pot 1 due to the head gasket leaking.
 
Last edited:

stamford

Pro Tuner
Points
362
From
Hampshire
Car
MG ZS200
Did you check the valves and chamber at all for any damage? Loss of compression is not always a gasket, but in your case it is the typical k-series issue that most would think it would be. Doesn't take much to get a chipped valve seat or valve, maybe a broken spring etc.

Some forget the liners can move, so could be that.
 

SLEEPER

Pro Tuner
Points
542
A lot of heat and steam can cause damage might be warped or cracked head.

Im not at all up on the weak points of your engine but you dont need a lot of heat to cause damage
 

halfordartistry

New member
Points
26
From
england sevenoaks
Car
rover 45
Hi

Thanks all for your comments. Two inlet valves were stuck open. Have now replaced them and lapped all valves in. Have replaced all followers as most were sticking.

Engine now runs fine generally. However on putting the foot down the engine roars (sounds like coming from air intake/filter box) and also struggles on hill climb if traffic slows you down, need to change down more than you think it needs.

Any advise welcome
 

nova135

Full member
Points
21
From
uk Weymouth
Car
Nova-K16-71Beetle
Hi,
Am just about to finish rebuilding my 45. And wondered if you used the MLS type head gasket. included in my gasket pack was a ( recommendation.)

All MLS type gaskets should be fitted with the latest type oil feed rail.
( part no LCN000140L ) failure to adhere to this recommendation may invalidate any Warranty.
lucky as i had already fitted the rail in my rebuild.

Terry
 

nova135

Full member
Points
21
From
uk Weymouth
Car
Nova-K16-71Beetle
The set that im using is the Lotus Elise/Exige upgraded head & bolt set. Fits all K Series engines except vvc.
Thought it might be general practice. perhaps not.

Terry
 

stamford

Pro Tuner
Points
362
From
Hampshire
Car
MG ZS200
There is a kit to use for upgrading the original issues and it does include an uprated oil rail and different head bolts as well as the MLS gasket. It was first used and proven on the Freelander before MGR/SAIC used it.
 

nova135

Full member
Points
21
From
uk Weymouth
Car
Nova-K16-71Beetle
Thats quite, right. In fact i have moved my uprated oil rail from my late 200 set up to this 45 set up. The 200 was realy used to make the adapter plate & the " fly wheel " " part rover and part beetle ", between the vw beetle gear box and the rover engine. Made mostly from some exspensive alloy. The Lotus kit says that the gaskets are made in the uk and the stretch bolts are made in Germany.

Enough said on here about my project. should realy start my own thread .
 
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