Valve Guide / HGF / Liner Diagnosis

[bitsofbeards]

Hi everyone,

It's my first post here, but I'm looking for help in the next steps I should take after I took my cylinder head off. Its a 1.8 K-series engine. Previously had the head gasket done about 1 1/2 years ago.

The problems started again when I was getting intermittent rough idling when starting, either hot or cold. Sometimes it was light, sometimes severe, but always went away immediately with a few revs. It was also using a small amount of coolant and oil, maybe a few hundred ml every few months.

Then one day sitting in traffic it overheated, completely to the red (I was looking for somewhere to pull over). But as soon as it hit the top I turned it off.

Initially I replaced the inlet manifold gasket, replaced the thermostat, drained and bled the coolant. This didn't change anything though, still had the rough idling, and now every time I took the expansion cap off there was a lot of pressurised air coming out that smelt like exhaust gas. Also the exhaust seemed a little bit steamy, but could have been normal.

Doing a (cold, dry) compression test I found lots of oil around the #1 spark plug thread. Can't remember the exact results but it was something like 100%, 105%, 50%, 60% relatively.

So anyway off it came, interestingly I found that some of the cam cover bolts were not even finger tight, just completely loose. And here's what I found inside:

The liners were not protruding from the block as far as I can tell. They are at least level, and in some places below. But there are no serious indentations in the head from the liners.

#2 cylinder has a very sticky oil residue:


With a sticky valve stem:


The others more dry:


There is a white crusty residue mostly one one side of the head:


And less on the other side:


The whole thing:



So what do you think the next steps should be?

• Check if the head is flat and just re-assemble?
• Get a new head and hope it fixes any valve problems?
• Remove the liners and add shims?
• Or are the piston rings gone?

Or let me know if there are any other tests I can do to help diagnose. Your help is much appreciated.

Thanks

James

[DMGRS]

I'm sure others will advise on the other issues, but from the point of view of liner heights - have a read of this:
Head Gasket Choice Guide

It goes into depth about which gaskets you can use with which liner heights - should give you some pointers.

[SD1too]

Originally Posted by bitsofbeards

So what do you think the next steps should be?

• Check if the head is flat and just re-assemble?
• Get a new head and hope it fixes any valve problems?
• Remove the liners and add shims?
• Or are the piston rings gone?

Hello James and to the club.

I think that you've already carried out an excellent investigation. My initial thoughts are that checking the head height (there is a minimum dimension) and surface would be a good start, but I wouldn't reassemble the engine without looking more closely at that rough looking valve stem. If I were in your shoes, I would continue with your own engine and read the experiences of club member Beinet1 who has a lot to offer on the subject of 1.8 cylinder heads.

When you say "get a new head" you don't mean "new" literally do you? I would not risk an unknown second hand part from e-bay. You could easily end up with more problems.

Don't attempt to remove the liners, and don't turn the engine whilst the head is off.

I don't see any evidence of a piston ring problem.

So, in summary, I'd say keep going James! Remove the valve gear and carry out a cylinder head overhaul. Don't skim the head unless you have proof that it's necessary, and take care with gasket selection and all the other things applicable to a successful 1.8 engine repair. All the tips and tricks are here on the forum, together with continuing advice as you proceed.

Simon

[minimutly]

Hmmm, i agree you need to strip and overhaul the head, have a real good look at the surface, take it to an engineering shop to check. Personally i would skim it if there is the slightest hint of fire ring damage on the exhaust side. ( it looks like it hasnt been overly skimmed previously, going by the squish slots on its face). Dont be frightened by people telling you you cant skim these, ive taken 40 thou off them with no issues.
The more important thing you need to check is the liner heights, front and back. They need to be level in theblock, and all about the same height. If the liners have dropped due to overheating, the block is scrap, dont waste time on it.
Rings on these engines rarely give trouble, covering 100+k easily, so id be suprised if this is your problem.

[The Rovering Member]

Have a look at this:

http://modusengineservices.co.uk/k-series/

Seems like it could be worth the money which sounds far from unreasonable.

[SD1too]

Originally Posted by The Rovering Member

Have a look at this:

http://modusengineservices.co.uk/k-series/

Seems like it could be worth the money which sounds far from unreasonable.

And it puts the likes of K-seal firmly where it belongs!

Nice one Gary.

Simon

[The Rovering Member]

Thanks, l posted about it a while back after spotting the link somewhere. If my headgasket goes at some point then l'll definitely be ordering one. At that money it seems a no-brainer to get the job done once & for all.

[bitsofbeards]

Originally Posted by DMGRS

I'm sure others will advise on the other issues, but from the point of view of liner heights - have a read of this:
Head Gasket Choice Guide

It goes into depth about which gaskets you can use with which liner heights - should give you some pointers.

Hi DMGRS,

I measured the liner heights more accurately with a feeler gauge and the flat side of a caliper. I got at least .05mm all around. So assuming I go with the MLS gasket how difficult is fitting the uprated oil rail? Is it worth it or just stick with the elastomer one?


Hi Simon,

Thanks so much for the encouragement! Getting a new head is more of a time saving thing really, rather than restoring the old one. When I say new I mean something like this. As mine has overheated at least twice now I'm not sure if it would be economical to not get a new one. Do you think I could just drop the old cams on that ebay one?

Also I'm almost certain that the head isn't flat now, I can see that the gasket hasn't sealed properly around #2. The defined ring around the others fades at the rear of that cylinder. It looks like it was running a lot cooler than the others (less scorching and brown bits). And also the valves are stained purple, I'm assuming from coolant.

I don't see how the cost of skimming an old head with dodgey valves is better than just getting brand new one. Assuming they come flat and everything?

So I'm thinking, new head, gaskets etc, new water pump, and new coil packs just to be sure it wasn't an electrical problem causing the rough startup after all. Hopefully that will be enough to get a few more years out of it. What do you think?


Oh, one further thing, one locating hole for the lug on one side of my head has a hole drilled about 3" deep that goes nowhere. The other side doesn't have this. It looks like someone has just stuck a drill down it at an odd angle. Anyone know what this is?

Thanks

James

[SD1too]

Originally Posted by bitsofbeards

I measured the liner heights ... I got at least .05mm all around.

Land Rover Technical Bulletin 0036 says:

"Liners can be level with, or 0.075 mm above, the face of the block. If the liners have dropped below the block face the engine must be replaced.

Check the cylinder liner by placing a straight edge across the liner and using a feeler gauge measure the distance between the cylinder block surface and the straight edge. This must be carried out in the inlet and exhaust manifold sides of the liner."

The bulletin also says that the head face must be flat across the centre and from corner to corner, again using a straight edge and feeler gauge, to within 0.05 mm. It goes on:

"Look for any sign of an indentation made by the bore eyelets of the head gasket. If there is an indentation ... the head has been overheated and the heat treatment properties ... lost. The cylinder head must be replaced."

Do you think I could just drop the old cams on that ebay one?

I don't see why not, although I don't have any experience of this myself. I imagine that you will have to get out the lapping paste as well. There are a couple of members experienced in engine rebuilding and hopefully they will advise you better than I can.

Be sure that the Land Rover head you are considering buying is the same design as that used on the Rovers and MGs. There are differences between the vehicular applications sometimes.

Simon

[DMGRS]

0.05mm is 1.96 thousandths of an inch - if any are that low, you need to use the BW750 gasket.
We do a variety of BW750 kits - click here.

MLS needs 3 thou or above all round, and perfectly even.