K-series engine

They overheat and blow headgaskets if you don't make sure there's plenty of water in them, or if they've been repaired badly in the past. They seem to have less of a rep for blowing up in sporty stuff and kit cars than they do in rover 200s, so I suspect owner attention to the cooling system is a big factor.

Didn't save me. :-(

Andy

Did you make sure the engine stretch bolts were regularly re-torqued?

-- JackH

I suspect owner attention to the cooling system is a

No. Is that part of the service schedule then ?

Andy

They still give issues in the MGF.... as the mother-in-law found out.

ISTR the dealer was persuaded to meet the cost as it had been bought new from them, was serviced by them and was only a couple of months out of warranty.

Unfortunately it isn't... but if people had them re-torqued on a regular basis (i.e: every oil change for instance), they might find the head gasket lasts much longer.

The problem is, as I understand it... because of the way a K-series is constructed, as in, because the head bolts hold the whole engine together from head to sump, they're longer than on most engines of this type.

They're also quite thin from what I've seen of them.

Anyway... over a period of time, all that expanding and contracting when an engine gets hot and cold, leads to them stretching a tiny bit more, and if said slack isn't taken up by re-torquing them, eventually it allows enough slack for the head gasket to blow.

HTH

-- JackH

You don't re torque stretch bolts, in fact if you tried to tighten stretch bolts "regularly" they would fail.

That and being citybound and driven like a granny are the reasons I suspect - my 400 was thrashed for 160k miles and only suffered a HGF when a hose split on the motorway - got it fixed and was fine thereafter too.

And they also have to content with the thermostat being on the inlet, which in the MGF/TF results in a LARGE volume of cold water being allowed into the engine when it reaches operating temp.

Richard

"Fred" in fact if you tried to tighten stretch bolts "regularly" they would fail.

The VVC I had recently had had them re-torqued every service in recent years... it's currently on 96k on the original head gasket, and the point is... they stretch so little, they only need nipping up a tiny amount.

-- JackH

You forgot the bit about plastic locating dowels... ;-)

-- JackH

How did you "re-torque" them? When you're re-fitting them, they should be tighten to (IIRC) 120 ftlbs (don't quote me on the actual figure) and then two additional 180 deg turns. Did you slacken yours off completely and do this?

Also, you're supposed to check for stretch before reusing the head bolts. I think you can do this with the head in place, but I don't think it is easy.

FWIW, as has been mentioned, they changed the locating dowels to steel which improved matters considerably, also, literally within the last few days, there have been some important developments in the replacement gasket design. There's a lot more info here:

I was told to replace them whenever you split the engine - which we did.

Have a read around on the lotus newsgroups such as mloc.net or seloc.org - lots of knowledge on the subject there.

HTH. Steve

You can't re torque a stretch bolt, most K series head gasket failures are down to a design fault of the original gasket.

There is only an initial torque setting for a new stretch bolt, once in place it can only be streched further.

.. it's currently on 96k on the original head gasket, and the point

Nipping up is not torque!

How do you 'nip up' stretch bolts? The initial setting tends to be to a fixed torque plus n degrees of rotation. Taking them beyond that is likely to lead to failure.

According to the Haynes book of lies, if you've got the engine apart, you need to run the bolts into the bottom oil rail. If they go all the way in, then the threads haven't distorted and the bolts are OK to use. If they've stretched, then you need to replace them.

Piffle! Rover released 5 updates (at least, i've lost count now) of head gasket for the K series, along with metal dowels, revised bolts etc etc and although they dont blow quite so often, you can guarentee that the HG will fail on 80% of K series!

Tim..

"Fred" >> >> Whats the K-series like?

I'm afriad in the case of the K series, yes you do re torque them.

Every oil change is abit excessive, but certainly every 12 months or so. Every one I check I find the center bolts are slack.

I have one vehicle with a Burton mod which moves the thermostat to the outlet side of the engine, and this has not had head gasket problems yet, although it did have the inlet gasket go. Its done about 90k miles ('98 car) and is not especially pampered.

Tim..