? HGF

[Dave B]

Seem to have a coolant leak and hope it is not head gasket. Car is K 1600 with Jenveys on manifold. When engine is up to temp there is a distinct drip from the region of  cylinder 4. It appears to be coming from the  manifold to head joint. Question is :- Is there a coolant passage in the inlet manifold in this area. If this is the case luckily I have a spare inlet gasket. Does the gasket need any goo on it. If it is a HGF then it will have to wait a while. TIA

 

Dave B

[oilyhands]

There is a waterway in the head that terminates next to the inlet port at that end of the head, there is no corresponding waterway in the TB casting, quite often there is damage to the inlet flange around the hole caused by electrolytic action, if it is leaking from the inlet gasket this may be the cause.

A new gasket with some Hylomar around the waterway should fix that.

if it is the HGF then a temporary fix can be had be throughly cleaning the edge of the block and head near the leak and piping in some automotive silicone sealant into the head/block join at this area. Work this into the joint carefully with a moistened finger and leave to cure. Do this on a cold engine...

Oily

 

[Dave B]

Many thanks Oily. The gasket I have is the green, sort of skeletal one, is this OK?

Dave B

[oilyhands]

That is no good for throttle bodies, you need the paper VVC gasket.

oily

[Jonathan Kay]

1998 1800K factory standard. Overheating two weeks ago. No leaks seen. Topped it up and the overheating went away.

Today I drained it, filled it up, and while it was still jacked up at the front started it in order to check that it the hoses got hot and for final top-up. To my surprise there was a dribble from the left rear of the engine. 

Cleaned and dried everything and started it again. Dribble reappeared within 30s.

Photo below. The dribble appears where the pink (!) arrow points. The protruding metal is wet halfway across from the L and the bright line is the flash reflecting in the liquid.

Then I remembered this thread. Any advice on diagnosing what's happening? The rear lower diagonal edge of the manifold doesn't seem to be damp, nor any of the hoses, rails or junctions above and nearby.

Thanks in advance for all advice and suggestions.

Jonathan

 

[SM25T]

The water rail connects to the head just above here. Gasket easily fails. Coolant could run down to where you see it ?

[revilla]

On mine, similar leaks have been the water rail as Ian says. Clean and dry it all, hold a wad of kitchen towel to the underside of the rail joint against the block. Start it up and wait for dribble, then look at towel.

[Jonathan Kay]

Ian and Andrew: thank you very much to both of you for this continuation of your relentless helpfulness.

I've now read the previous discussions about that rail and its alignment.

That's my morning rearranged.

Thanks again.

Jonathan

[Jonathan Kay]

After lots of drying, cleaning and probing;

1. There's no liquid coming down from the water rail or the joint.
2. But there is from the lower rearmost diagonal edge of the exhaust manifold.

What next, please?

Thanks 

Jonathan

[SLR No.77]

Unless you can find it tracking from somewhere else and running along the edge of the head gasket to where you're finding it, it does sound like the elastomer seal on the head gasket may be failing at that point ... which unfortunately means a new head gasket. The original K head gaskets had a red elastomer seal around the waterways and the outer edge, this has now been updated to a blue elastomer seal due to this problem of failure. Make sure you buy the later blue elastomer version.

Stu.

[revilla]

Jonathan, that sounds a bit odd. There are no waterways around the exhaust manifold as there are with the inlet and if it's coming out from around the exhaust, that's ABOVE the head gasket line. What sort of flow rate are you getting? I mean is it just an occasional drip or a good dribble when it's running? If it's getting to the exhaust manifold it's coming from somewhere else and with it just standing still in the garage with no air flow around the head gasket sounds like an unlikely source to be pushing water upwards. What I have seen before was a tiny pinhole failure of a rubber hose that senr out a jet of water finer than a needle and almost invisible. Have a good look at the rubber bypass hose and joint onto the water rail just to be sure that's not firing a little jet at the moment exhaust manifold (on mine it was the top radiator hose at the front).How sure are you that it's not the water rail joint? The coolant can tend to flow down from over the surface of the head as an invisible film, coolant is funny stuff, you only find it where it hits something and collects, such as the exhaust manifold.

Just for reference, if you do find you need one, these ones are know to be the right type for a good price. Payen BW750: https://www.amazon.co.uk/dp/B00F6O8ZDE/ref=cm_sw_r_cp_apa_U23OBbRKCD4HG

[SLR No.77]

Andrew, is Jonathan's description not of the head/block join?

[revilla]

Stu, I was going from Jonathan's comment "But there is from the lower rearmost diagonal edge of the exhaust manifold."

[oilyhands]

I have seen coolant seep around the head/block join to the exhaust side from the inlet manifold by capillary action. Worth a look..

Oily

[Jonathan Kay]

Thank you very much Stu, and again, Andrew. Greatly appreciated.

I have seen coolant seep around the head/block join to the exhaust side from the inlet manifold by capillary action. Worth a look.

Thanks, Oily. Very wet under the rearmost fastener of the plastic inlet manifold/ injector housing. (Not sure what it's called.) That's the wettest point that I've found (other than the floor) and I think that it's higher than what I'd previously located.

And despite hours of trying to find it on the other side I'd never looked or felt there. It's assumptions that get you every time!

Does that take me back to post #2 above?

• What sort of Hylomar sealant, please?
• And I know this is is a difficult one for anyone else to answer... should I take this on myself? I enjoyed assembling the Seven but chicken out of changing the timing belt.

Thanks

Jonathan

[revilla]

Sounds like changing the inlet manifold gasket and having a good look at why it might have failed is the first thing to do. Absolutely do it yourself... Chia says she fancies a day in Oxford so if you want somebody to come and give you hand, let me know

[oilyhands]

The original O rings used go hard with time and the plenums distort a little over the many heat cycles, these re the primary causes of leakage. Be careful where you source the new O ring as some of the aftermarket ones are not thick enough and will leak after a short time in service, I always bolster the area around the waterways with a little automotive silicone sealant to help mitigate against leakage.

Oily

[Jonathan Kay]

And the answer.

Firstly, thanks again to everyone who suggested what was going on.

Here’s what the problem was, and how we fixed it.

And I say "we" because I wasn't dumb enough to turn down Andrew's extraordinarily generous offer.  And had the added pleasure of his company for a day. And now he knows his way around plastic inlet manifolds... ;-)

The inlet manifold gasket was shot. The metal face wasn't eroded. The new gasket from Rimmer Bros worked fine. No additional sealant was used.

Two diversions along the way. I’d previously been misled by where the drip occurred, see above. And after the new gasket was fitted… it continued! But that was due to a surprising amount of coolant sitting in the curved rib at the lower edge of the sump (corrected, see below). 

And a bit of hunting when it was all reassembled, which was cured by excising the damaged end of a vacuum hose.

 

Could I have done that myself once the fault was known? I’d have needed a couple more tools and an awful lot of remote handholding. 

 

Jonathan

 

PS: The test drive was fun. Took a load of stuff to the recycling centre. Temperature fine. No drips. And then on the way home the temperature gauge dropped off the low end of the scale… loose connection on the sender! :-)

 

 

[revilla]

I took this photo at the time showing the recess in the rear of the sump which had filled up with coolant and which continued to drip when we believed we had cured the problem. Had us scratching our heads for a few minutes!

[StevehS3]

Great you’ve got yours sorted.

Last time I changed the plugs the one nearest the scuttle was a slight pink colour which I assume is coolant. Over 5,000 miles I haven’t topped up the coolant so it must be very slight. Any thoughts if this is the inlet manifold gasket fault and if so, was it easy to change (it looks awkward!)?

P.S. It’s a late 1600 K, 12,000 miles.

[nickh7]

Bl dy love this club. Great job .

[Jonathan Kay]

Last time I changed the plugs the one nearest the scuttle was a slight pink colour which I assume is coolant. Over 5,000 miles I haven’t topped up the coolant so it must be very slight. Any thoughts if this is the inlet manifold gasket fault and if so, was it easy to change (it looks awkward!)?

As is obvious from above I wouldn't know! ;-(

Do you have a plastic or metal inlet manifold?

Jonathan

[StevehS3]

Many thanks Jonathan. It is the plastic manifold on one of the very last Ks. 

I will take another look at the plugs as well.