Freelander 1 Compression help

Kelljwk · Feb 10, 2019

Hi guys... list of jobs seem to be never ending on my 2004 1.8 hippo. I’ve found this forum is the answer to most of my questions.
I have recently changed the sender unit + filter because I was having issues with idling and starting.

Starts perfect from cold, runs well. When it reaches temp, it’s lumpy and the revs plummet and cuts out at every junction or when I stop.

I did a compression test and my results very low.

No 1 - 125 (timing side)
No 2 - 90
No 3 - 75
No 4 - 75

I’m pretty shocked that it’s actually running to be honest. I’d expected them to be 125+ for an engine of this age etc...

I repeated the test with a some oil in the cylinders and got the same results. Does this show I have a valve issue? Or a f***ed cylinder head?

No oil mixing, not loosing coolant, no vacuum leaks, no over heating.
Head gasket, belts + oil were changed a few months back. Along with the head being skimmed but the valves weren’t replaced.

Any help would me much appreciated for my next port of call.

Nodge68 · Feb 10, 2019

The compression figures should be around 170 Psi, so you're well down on them.

It would be unusual for all the valves to be leaking, especially giving uniformly low readings.

Did you have the throttle open for test? This is important, or the cylinders can't fill correctly.

If those are true readings, then the first thing I'd check is the cam timing. A slightly retarded inlet cam will cause a significant drop in compression pressure.

As a rule, the K series doesn't suffer from appreciable drop in compression as it ages, unless something is up with the valves or the head gasket.

Definitely more investigation is needed.

Kelljwk · Feb 10, 2019

Thanks for the reply...

Yeah that was throttle open and from cold. 170? I’m way off the mark then. I’ll check the readings again just in case.

I have checked the timing and it looks bang on but will have another look.

It seems to have happened over night which is a bit puzzling. Following the head gasket change etc it ran perfect for a few months, parked it up overnight then when I went to go to work it was the Polar opposite. I have to disconnect the iacv once warm to keep an idle , which points me to fuel/vacuum issue or as you say the timing out.

What’s the chances all the valves are knackered from previous overheating?
I believe the head I was given was from an MG that had got hot and put a hole in a piston but was assured it had been checked over and skimmed

Nodge68 · Feb 10, 2019

Kelljwk said:
I believe the head I was given was from an MG that had got hot and put a hole in a piston but was assured it had been checked over and skimmed

If the head was from an overheated engine then it is scrap. The heads undergo a special heat treatment process at the time of manufacturing. If it's subsequently overheated, then the heat treatment is lost, and the head MUST be discarded. The head can be faced off to make it flat, but the heat treatment is lost, so it's a pointless exercise. If a soft head is re-used, then the fire rings will recede onto the head face, causing combustion products to enter the cooling system. This second failure happens very quickly, often before the next oil change is due.

So going by the latest information, I suggest the head is replaced with one from a crashed car, not an overheated one.

Kelljwk · Feb 11, 2019

That’s what I was worried about, I was unaware about it loosing the heat treatment.
A friend of mine did Exactly that, twice within around 7k miles.

There’s a couple of MG Zr’s in my local scrappy, I think they are 1.4L though... Are these the same as a 1.8? Wasn’t sure with valve sizes etc...?

I have the original one from my freelander but unsure of it’s condition, which I was going to send away to a guy in Leicester that recons them?
eBay number: 223273153451

Nodge68 · Feb 11, 2019

Kelljwk said:
A friend of mine did Exactly that, twice within around 7k miles.

That's what happens if a soft is re-used. These repeat failures are responsible for giving the K series the bad reputation it had.

Kelljwk said:
There’s a couple of MG Zr’s in my local scrappy, I think they are 1.4L though... Are these the same as a 1.8? Wasn’t sure with valve sizes etc...?

All later K series head castings are the same, including the valve sizes. So a 1.4 head will work just the same as the 1.8 head that came off. The cams are different, so would need swapping over, along with the followers. The cam belt tensioner has a couple of different designs, either manual or automatic, but those can be swapped about to suit the head.

Kelljwk said:
I have the original one from my freelander but unsure of it’s condition

If it was overheated, then it's scrap. If not, then it's hardness can be checked by most engineering works.

rob_bell · Feb 11, 2019

In my experience, the appearance of the K-series head tells its own story when you lift it to investigate further. There is usually a very fine, barely detectable ring mark left by the liners if the head is in good condition. However, if the head has over heated and gone soft, you will find very obvious liner indentation on the cylinder head face - bad enough generally to catch your finger nail in.

If you can feel this, then as Nodge says, the cylinder head is essentially scrap. To be sure, get the head hardness tested. I don't know if you've seen my project thread ("Kilo Hippo Delta"), but you'll see the process I went through.

I didn't compression test the engine with the original cylinder head, but it actually ran as sweetly as a nut. Without any coolant, and oil that looked like school gravy. These engines are actually quite amazing.

The head is a suspect here, but I wonder whether there isn't another problem to explain the stalling/ compression loss? But very odd that all four cylinders are down...

Kelljwk · Feb 11, 2019

Thanks for all the info...

rob_bell said:
However, if the head has over heated and gone soft, you will find very obvious liner indentation on the cylinder head face - bad enough generally to catch your finger nail in.

Yeah the original is knackered in that case, the indentation is pretty obvious even if you were stood about a mile away

I’ll have a look at your “Kilo hippo delta” it’ll make for an interest read I think!
I’m curious to know why garages are quick just to skim the head?
Obviously it will be pressure tested but that won’t make a difference if it’s fitted back to the car and it’s in fact soft, would it?

rob_bell said:
The head is a suspect here, but I wonder whether there isn't another problem to explain the stalling/ compression loss? But very odd that all four cylinders are down...

This is what I can’t understand... I never did a compression test previous to this as the car was perfect after the hg change. (due to an external leak mentioned by previous owner, bonding had come away from gasket).

It’s happened overnight which is the puzzling thing, I have no “school gravy” lol or loss of oil / coolant. Just ran like a bag of spanners and started cutting out when warm. Which sounds like a timing issue as nodge said, I’ve checked again today and it looks right. I’m at a loss to be honest!

potus · Feb 11, 2019

I'd guess your timing is probably okay if the running issues happened overnight, It's highly likely to be HG failure IMO.

rob_bell · Feb 11, 2019

Kelljwk said:
Yeah the original is knackered in that case, the indentation is pretty obvious even if you were stood about a mile away

I’ll have a look at your “Kilo hippo delta” it’ll make for an interest read I think!
I’m curious to know why garages are quick just to skim the head?
Obviously it will be pressure tested but that won’t make a difference if it’s fitted back to the car and it’s in fact soft, would it?

That's a shame - but yes, sounds like it will be toast

Actually, damaged heads can be recovered - there are a couple of specialists who will let in a strengthing ring into the area surrounding the combustion chamber, and that seems to work (not tried it myself, and it is generally cheaper to find a good second hand head!). As you say, the 1.4, 1.6 and 1.8 16v engines all share the same cylinder head (although beware of early 1.4 "low-port" castings - they're not as good from a port design perspective, but must be incredibly rare these days...)

Why do "mechanics" reflexively send cylinder heads off to be skimmed without hardness testing first? I suspect the simplest answer to that is ignorance: they're not [usually] engineers...

Kelljwk said:
This is what I can’t understand... I never did a compression test previous to this as the car was perfect after the hg change. (due to an external leak mentioned by previous owner, bonding had come away from gasket).

It’s happened overnight which is the puzzling thing, I have no “school gravy” lol or loss of oil / coolant. Just ran like a bag of spanners and started cutting out when warm. Which sounds like a timing issue as nodge said, I’ve checked again today and it looks right. I’m at a loss to be honest!

This is what makes me uncomfortable. I'm worried something else has let go. Which would fit with a low compression on one cylinder, but why all of them?

Hopefully it'll become more obvious when you lift the head...

Kelljwk · Feb 12, 2019

Funny you should say that, I was watching a video of a engineer putting hardened rings into a cylinder head, looks well when it’s done... can’t imagine the price though!

rob_bell said:
Why do "mechanics" reflexively send cylinder heads off to be skimmed without hardness testing first? I suspect the simplest answer to that is ignorance: they're not [usually] engineers...

Haha Sounds like a few garages round here... They see a k series come in and automatically think £££ head gasket when in fact you only needed some new plugs!
And when it goes tits up the customer gets - “Well it was fine when it left here.”
Hence why we do most of the stuff ourselves isn’t it?

Looks like I’ll try and find a decent head from somewhere and see if I can put an end to it so to speak. There is a running rover 200 with 38k on it that’s being broken nearby. Maybe worth a look?

Although I jumped in the car last night to work and it ran pretty well, the revs dropped pretty low but never stalled... same on the way back today. Didn’t sound as rough when it was warm but wouldn’t restart unless I blipped the throttle. It makes me feel at ease that it’s puzzling you guys and it’s not me bein a moron

Nodge68 · Feb 12, 2019

rob_bell said:
Why do "mechanics" reflexively send cylinder heads off to be skimmed without hardness testing first? I suspect the simplest answer to that is ignorance: they're not [usually] engineers..

Hardness testing is requires expensive test equipment.
But a quick accurate enough way to tell is from fire ring recession, as you said earlier.

Kelljwk said:
Didn’t sound as rough when it was warm but wouldn’t restart unless I blipped the throttle. It makes me feel at ease that it’s puzzling you guys and it’s not me bein a moron

If the compression is very low, then blipping the throttle will often increase the compression, just enough for the engine to fire.

Freelander 1 Compression help

Kelljwk

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Nodge68

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Kelljwk

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Nodge68

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Kelljwk

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Nodge68

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rob_bell

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Kelljwk

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potus

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Kelljwk

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