Compression test readings

I did a compression test this morning, the readings are cylinder 1, 2 and 3 are 150psi just over 10 bar, cylinder 4 = 175psi around 12 bar.

The haynes manual say a guide of less than 10 bar is less than healthy and a difference of more than 2 bar between on any two cylinders indicates a problem.

From the readings above do you thing i have an engine problem as all 4 cylinders are over 10 bar but a differnce of 25psi just under 2 bar between cylinder 4 and the other 3 cylinders.

Do you think i should be taking the head of to inspect it and fit a new head gasket, at the moment it's driving ok just using a fair bit of oil, what would you be doing if you had theese readings.

how many miles has it done ,normally you expect no4 to be the lowest, have you repeated test ,and tried with a few squirts of oil in each cylinder

Its done just short of 75000 miles, i did the test twice with the enigine warm with the same results cylinder 4 giving an higher reading of 175 psi, i didn't do a test using a few drops of oil, i'll give that ago next.

I had the head gasket replaced around 4 years ago at a garage, is there a life expectency on replacement new head gaskets.

150 psi is a bit low. Did you have the throttle wide open for the compression test? On a healthy engine, I'd expect to see all cylinders to be within 10 psi of each other. 175 isn't far off the mark for a healthy K series. You could have valve seat trouble on the low cylinders.
If the HG was loosing sufficient pressure to drop the readings, you would be blowing the coolant out of the pressure cap.

The throttle was wide open, i know there is a problem and i'm leaning towards the valves aswell as i've been using oil, the only way i'm going to find out is if i take the head off and check the valves, either way its going to need a new head gasket.

Once the head is off and the cam carrier and cams are removed, should all the valves be closed air tight, does the petrol test trick really work if the valves are good none will leak through when poured into the top of each upside down cylinder head.

If the valves are knackered i'd like to have a go at reseating new inlet/exhaust valves myself, can you recommend were to buy new valves.

I'm in the process of gearing upto do the job and have things to get before i even think of starting so i'm well prepared, i need a digital torque adapter to make sure my torque wrench is calibrated as it hasn't been used in ten years.

I've been trying to find someone who sells the cylinder liner clamps with out look i've even googled it but can't find a supplier.

from the info on the forum, manual and the engine overhaul pdf i think i should be able to do it, i just may have lots of questions before and during the job.

Cylinder liner clamps can be made from the used head bolts, a large flat washer at each end and a 90mm? length of 12mm copper pipe as a spacer between those washers. Just do up hand tight and then a wee bit with a socket. I guess you will do the w'pump, tensioner and cam belt too. replace that thermostat as it's easy to get at with the head off. New S' plugs?

When I had my 1.8's head off I cleaned out the plastic moulding 'flash' from the inlet manifold and weld splatter from the ex manifold too as well as port matched the head. I also had the valves unshrouded by 2mm and smoothed out the valve seat lip in each throat. And then I lowered the hump in the ex runners by about 1mm. Oh, and I decated it too. Not sure you can do that in the UK?

I must have done something right as I'm now getting over 30 mpg, best so far was 38mpg. Two other things I did were to fit a CAF and a K&N Apollo A'filter.

Carefully check the liner heights before you order your HG.

cylinder leakage test would be the best,you can tell where pressure is been lost, but if its just some oil loss id change oil and give it some hard work unless your looking to rebuild engine

Liner clamps are easily made with some 15mm copper tube and some large washers.

I'm having to top up the oil up on monthly basis a litre maybe a litre and half, so i keep a 5L carton in the car just in case.

I've ordered an otc leakeage tester from the states, i'm waiting for it to be delivered to see if i can pin point the problem, every thing seems to take longer when your waiting.

I was going to split the job into two stages as i don't want to have the engine mounting off while i have the head off aswell, so was going to set the timing marks up then remove the cam belt from the sprockets and tie the rear cam cover back, then take the head off and do what ever needs to be done then refit the head with new gasket, i just don't want to make any mistakes and move the liners.

Second stage...Once the heads back on was jack the engine up and remove the engine mounting and rear cam covers so i can change the coolant pump and renew the belts, my thermostat is near the front radiator so will replace this last before i top up with coolant, i don't feel comfortable doing it all in one with engine mounting bracket removed in case the engine moves.

One thing i have noticed i have a white powdery residue around the expansion bottle, i brushed it off about a week ago and its come back but i haven't lost any water, does the white powder indicate anything.

Powdery residue likely to be dried coolant. Coolant pump is easy to change when the head is off. To get the head off you have to take off the cam sprockets and the upper inner cam cover along with that upper engine mount. It's all got to come off to get the head off. Support the engine weight with a trolley jack...

The liners won't move unless you turn the crank with the head off, and there's no need to do that anyway.

Head off = 1/2 a day - head back on over 1/2 a day [ allow for fluid refilling ...]

To remove the head you need to remove a lot of things - it sounds a lot but it's not as bad as it seems:
Batt + lead
air cleaner
Remove bottom rad hose to drain coolant
remove top rad hose
remove coolant pipe to 'giggle valve'
remove plug leads and plugs [ the motor is easier to turn by hand with the plugs out put rags in plug tubes]
remove coil and distributor
remove inlet manifold - leave everything on it
upper outer cam belt cover
remove sump guard
remove front right road wheel
remove right splash guard
remove PaS belt & alt/AC belt
remove alternator bracket
exhaust down pipe [2 studs under sump first]
use a 22mm socket and wind motor over to align crank [90º BTDC] & cam sprockets - fit locking tool
remove crank pulley [it will be very tight! and you will need an assistant to step on the brakes]
support motor weight on a trolley jack...
remove upper engine stay bar
remove upper engine mount [ hydralink? top connection]
remove hydralink? alloy casting from head
remove lower cam belt cover
loosen and remove cam belt tensioner - replace with new
remove cam belt - replace with new
remove cam sprockets [these have to come off as the cam cover is bolted to the head]
remove upper inner cam cover - nearly there
remove cam cover from top of engine [remove bolts in the correct sequence]
remove head bolts in the correct sequence - loosen all a bit first then remove
lift head off! [place it on some soft absorbent material]
New valve guides and seals is it? Bit of head mod'ing??
You may like to renew the cam oil seals at the same time.
With all that off the w'pump is easy to get at and change.
Belts are easy to replace when you are putting it all back together.
All jobs done in one go - be it a long go!

I'm waiting for the tools i've ordered to be delivered, flywheel locking tool, camshaft locking tool, digital torque adapter so i can calibrate my torque wrench. The flywheel locking tool should make it easier to get the crankshaft pulley off, i'm going to remove the starter motor and lock the teeth.

I will need to get another torque wrench that goes down to 10nm, 7lb ft to do the cam carrier bolts as my torque wrench is 10 to 150lb ft so will be ok for the cylinder head bolts.

Thanks for the tip about using copper pipe to make the liner clamps, i won't order the gasket set until the heads off and checked the liners.

When i set the timing marks up like this photo will this be 90 BTDC so the pistons are half way up the bores so it's safe to remove the head.