1.8 Freelander engine coolant passages connection inlet passages to exhaust passages

Hi again all,
I’m changing the head gasket of my 1.8 as it started weeping coolant out of the cylinder head gasket, all 4 sides. When I removed the head today, it seems that it has lost torque on those bolts, so I’ve ordered new bolts, new gaskets, etc, etc, etc.

Just a quick Q in relation to this. You know the coolant passages in the 1.8 K series engine block (not the cylinder head)? Are the coolant passages from the exhaust side connected to the coolant passages on the inlet side of the block? I’m flushing them today and I notice that coolant moves along the inlet passages in the block but doesn’t seem to flow through to the exhaust passages and vice versa. Should coolant be able to flow in the block from the coolant inlet passages to the coolant passages on the exhaust side? Or, does the cylinder head make this all happen? I tried a bottle of K seal just to see what’d happen since I was going to replace the head gasket anyway. It stopped the leak – but overheat started… as it blocked up many of the coolant passages in the block. I’ve since removed a lot of the remnants of K seal but hope there isn’t some blocking the coolant flow in the block from the exhaust side coolant passage to the inlet side coolant passages?

I think i answered my question today when time came to cleaning the cylinder head... a series of interconnected coolant passages... The 1.8 K series cylinder head has more coolant passages than the Sydney underground train tunnel system! (lol) So when the head is mated to the block, it promotes easy coolant flow between the inlet side coolant passages of the block, and the exhaust side coolant passages..

Do you have a picture to put up? So you mention k seal. Did you leave it in the whole time ? I have been keeping track of head gasket sealer and so far the only ones that seem to work are


. Ones without particles (kseal seems to have some)
.jobs where the sealant was put in only water

.jobs where the sealant and water were removed and flushed out the few hours after the leak was sealed.


I am very curious as to what you did to be able to keep track.

K Seal is a no no on the K Series engine. I replaced my V6 instead of messing about with the blocked coolant passageways. It's dreadful stuff.

Thanks Nodge. Just a question still to yourself or anyone else who can remember the last HG renewal they did on the 1.8 K Freelander, still original question has got me interested, should the coolant passages on the inlet side of the block be connected to the exhaust side of the block? This is assuming the cylinder head is removed, it's just got me really interested, glad to know if anyone remembers this when they last worked on this. It's got me really interested. By the way, upon further investigation, it appears that another leak sealer may have been used in this engine prior to K seal and not propertly flushed out.

Have you seen this post? I am not sure it answers your question, but one never knows

Freelander 1.8i head gasket change - Freelander Forum - LR4x4 - The Land Rover Forum


Are you or have you already changed the oil rail as well?

Yeh i saw that - but i'm not convinced that in the 1.8 k series cylinder block, that the coolant passages for cylinders 1 and 4 are linked to both the inlet side and the exhaust side. .... if anyone knoww or remembers otherwise from experience, comments invited. This morning before i left work from home, i sprayed WD40 in those tiny cavities then tried to pry with a flex tiny tiny brush and wont budge... I tried the same in the cylinder head as those tiny coolant passages were blocked by coolant sealer gunk and as soon as WD40 hit it, straight away the stuff dislodged and freed itself when i poked it.

niccage said:

Yeh i saw that - but i'm not convinced that in the 1.8 k series cylinder block, that the coolant passages for cylinders 1 and 4 are linked to both the inlet side and the exhaust side. .... if anyone knoww or remembers otherwise from experience, comments invited. This morning before i left work from home, i sprayed WD40 in those tiny cavities then tried to pry with a flex tiny tiny brush and wont budge... I tried the same in the cylinder head as those tiny coolant passages were blocked by coolant sealer gunk and as soon as WD40 hit it, straight away the stuff dislodged and freed itself when i poked it.

Click to expand...

They are all interconnected, turn the cylinder head upside down so the valves are looking upwards, you'll need to block the two holes on the side on the head (inlet side) pour water into the coolant chambers, the rest of the chambers 1,2,3 4, should all slowly fill to the same level.

I have always said this....... coolant sealants (Radweld, K-seal, steel seal) are the devils work, only a get home measure and flush asap.

there are narrow restrictive passages in the k-series head (even more restrictive in the rad and heater matrix) the head castings are rough and not even the same size. Try an airline to blast out any crud/sealant, then flush with copious amounts of water before the head rebuild.

I did ask some of the original Rover-Mg workers via other forums, who said they had glass viewing panels on the factory test heads, so they could watch the coolant flow?

If you look at any head gasket, they have smaller ~6mm holes inlet side and larger ~10mm on exhaust side.
I asked these Rover boys "should we drill these" after all the kidney shaped chambers which lie above are vast in comparison.....I was told to leave well alone!

But having spoken directly to an approved Lotus mechanic (Elise has same k-series engine) they do a modification of a 10mm hole in one of the chambers in the gasket. He wouldn't tell me which one!!, maybe there are several Lotus approved mods they keep under wraps?

As your a man from down under, I would say the k-series would benefit from extra flow in warmer climates
I have drilled my thermostat ring to allow continuous flow (x2 3mm holes)

Cheers Northern Islander, thanks for that. I notice you mentioned the head, I already got all of that unblocked courtesy of some WD40 in conjunction with a flat screwdriver and high pressure trigger via a mere garden hose. I got all of the tiny passages in the head unblocked and can confirm coolant flow throughout the head. What i meant was the block, the engine block. There's coolant passages on the inlet side of the block as well as more coolant passages on the exhaust side of the block. Correct me if i'm wrong, but it seems that the coolant passages on the inlet side of the block are not connected with the coolant passages on the exhaust side of the block (with the cylinder head removed). So in other words, there's no tunnel or passages that passes on from the inlet to the exhaust side at the edge of the block at the side of either cylinder 1 or cylinder 4. It would be great if anyone out there could confirm or eliminate this... Cheers, Cage.

niccage said:

Cheers Northern Islander, thanks for that. I notice you mentioned the head, I already got all of that unblocked courtesy of some WD40 in conjunction with a flat screwdriver and high pressure trigger via a mere garden hose. I got all of the tiny passages in the head unblocked and can confirm coolant flow throughout the head. What i meant was the block, the engine block. There's coolant passages on the inlet side of the block as well as more coolant passages on the exhaust side of the block. Correct me if i'm wrong, but it seems that the coolant passages on the inlet side of the block are not connected with the coolant passages on the exhaust side of the block (with the cylinder head removed). So in other words, there's no tunnel or passages that passes on from the inlet to the exhaust side at the edge of the block at the side of either cylinder 1 or cylinder 4. It would be great if anyone out there could confirm or eliminate this... Cheers, Cage.

Click to expand...

The block is a single chamber, as you pour in water, it should fill both sides. With the engine in-situ on level ground, its tilted forward and so appears coolant/water is higher on exhaust side

Don't make the gasket holes larger. You will notice that the inlet side of the engine has coolant holes much smaller than that of the exhaust side. This is deliberate to promote coolant flow to all parts of the engine. If there is any casting flash in the head, this shouldn't be there so can be removed with care.
Before fitting the head, check the liners are at least flush or protrude up to 3 thou.

Northern Irelander said:

The block is a single chamber, as you pour in water, it should fill both sides. With the engine in-situ on level ground, its tilted forward and so appears coolant/water is higher on exhaust side

Click to expand...

This ^^^^

Ok thanks, so the connecting tunnels (if i can call them that) that let coolant flow from the inlet to the exhaust side of the block, are these tunnels at the block edges next to cylinders 1 and 4, or are they at each side of each of the cylinders except right at the edges of the block for cylinders 1 and 4? I need to get a hold of some flex wire tomorrow and wd40 and shove it in to those small holes i can see some debris down there and get to it, i'm also thinking about getting a mobile mechanic guru to spray high pressured compressed air in to those cavities to get all the gunk out of there. For the head, i was able to unblock it all myself using a mere trigger on a garden hose after WD40'ing the water jackets then poking them repeatedly with a screwdriver until Houston.. we have movement! The block is a little tricker because of the lack of access and smaller holes.

Update, i've done research which directly challenges the stated fact that the coolant cavities in the engine block are interconnected with one another when the cylinder head is removed. Consider my investigation as follows;

https://www.youtube.com/watch?v=VSM3UW1nkls
On the above video, scroll to 3.03 (3 min 3 seconds) then watch from there, note the level of coolant in the exhaust side of the block is a lot higher than on the inlet side.

Another video link below, fast forward and pause at 2.10 as same as prior video, the level of coolant in the exhaust side of the block appears higher than on the inlet side
https://www.youtube.com/watch?v=tdk7RTEnyjE

And last but not least, on the following video, watch from 0.03 or perhaps just pause at 0.03 and note the significantly higher level of coolant on the exhaust side of the block in contrast with the inlet side. ROVER 45 HEAD GASKIT REPAIR.mpg - YouTube

What does eveyone now think given the above evidence? It puzzles me that, without the cylinder head, coolant cannot travel from the inlet to the exhaust sides of the block and vice versa... isn't coolant trapped in some of the coolant cavities in the block? Or does the cylinder head facilitate adequate movement?

There's space between the liners, so coolant can transfer from side to side via those. These are easily blocked by debris and temporary leak sealers.

This thread on MG-ROVER.ORG tells you pretty much everything you need to know about the K Series coolant flow. This is described by one of the original design engineers iirc.

http://forums.mg-rover.org/showthread.php?t=338713

Thanks for that link lodge, the following i quote from one of the posters on that link seems to sum it up;

"if you look at the flow path it is slightly different to old school engines as coolant flows from the pump at the rear of the liners and a small amount is bled though onto the inlet valve seats and the rest moves roung the liners to the front of the engine and then up onto the hot exhaust valve seats and then merges with the coolant that has come from over the combustion chambers from the inlet and goes out the head, as you can see this evens out the temp aroud the whole engine. only very specialised race engines were doing this back in 1989!"

The summary could be consistent in why there always seems to be more coolant in the "exhaust valve seats" as opposed to only "a small amount" being "bled through to the inlet valve seats". That seems consistent with mine and i couldn't work out why there's always more coolant in the exhaust valve side than inlet, well evidently, now i know. I'm going to try and extra all coolant from mine including all debris (wish me luck!) and then do the simple test myself by adding water to the inlet side and see if it flows through. Oh Nodge, sorry for calling you lodge, i'd correct it if i could but once it's posted it's too late.. Cheers.

I know this is not what you asked and it might not be needed but have you read Kaiser's post in liner movement and he put locktite? I thought I would share just so you know if you ever have liner movement.

http://www.the75andztclub.co.uk/forum/showthread.php?t=130997&highlight=1.8T+pictures

Thanks for that, after reading, I knew where I could expect coolant to pass through and i used a screwdriver to clear the debris in that tiny connecting passageway from the inlet to the exhaust sides of the block between each liner and voilla, as soon as the level of coolant starts to grow in the valve side of the block, it takes the route of the passageways and ends up on the exhaust side. From there on, the water simply starts to grow in the exhaust side of the block before spilling over the block and out... obviously consistent with what the engineer said, when the coolant grows in volume on the exhaust side of the block, it will eventually merge with more coolant in the cylinder head and then flows out and eventually to the radiator. I've got everything unblocked including in the cylinder head as well as the block but just to be safe, i'm getting my mobile mechanic friend to come over sunday PM to blow compressed air in to the block and head just to clear any other debris that may be present. He said the air pressure will be 800 psi so hopefully, anything inside will go flying out..

100 psi is more than enough pressure to clear out the head/ block! Just make sure the gaps between the liners are clear. This is where the 1.8 K series causes problems. The 1.4 engine never suffered in that area as the gaps between the liners are larger.
Good luck with the rebuild