Freelander HGF... with a twist (thermostat)

Hi, just joined here although i have been reading posts here for the last few months.

Just had the dreaded HGF on the petrol 1.8 although caught it in time before it caked the engine with gunk and everything else so just a quick gasket change, oil dump and clean from the garage, and saved up for it just in case so hasn't hit me wallet wise.

Whilst working on the engine the mechanic checked the thermostat and found that someone had drilled a hole in it. Not sure why they did it but the mechanic believed that was the cause of the slow HGF occuring (only had the vehicle 4 months).

anyone know why there would be a hole drilled or cut in it? some mod that is supposed to improve the cooling or performance? either way it's a bit dodgy in my eyes if it leads to HGF.

the hole in the thermostat wouldn't cause HGF.

The hole has probably been drilled to prevent overheating being caused by the thermostat jamming shut. In the even the thermostat jams shut, at least some coolant will still be circulated, with hopefully enough of a glitch in the the temperature gauge to alert the driver something is wrong.

However, if the hole was drilled to avoid replacing a defective thermostat, then not so good.

Ok thanks for that. The thermostat was replaced anyway so if it's defective it's in the skip somewhere now.

Don't think i'll drill a hole anyway, thermostat is there for a reason i guess. And the engine didn't overheat, the vehicle jolted like an american gangland car with hydraulic suspension for a couple of seconds which gave me alarm bells, maybe i was lucky compared to other HGF failures (or at least most of them compared to what i read googling on the subject).

Hopefully i can hang on to it for a good while. Lots of people slag the Freelander off but just like every other car it's got it's problems, the only car i had that had no problems was a Meriva (yes, the horror lol). Not a single breakdown or part replacement and had it for 6 years.

:welcome2:It is recomended by LR that if it hasn't already been moved that a "re-plumbing kit" is fitted which moves the thermostat out from the block and it ends up sited in the pipework behind the radiator. I think this was standard on later models (mine was a 2001my).It is a genuine landrover Mod. I understand that in the original position the thermostat is on the wrong side of the temp sensor. When I had the HGF the engine had overheated due to thermostat failure but the temp gauge showed normal! If I remember the cost of the pipes was about £60. Definately worth investigating.

Tony

Looking under the bonnet the thermostat is fitted where you mention so looks like it's been modded already or was fitted as standard ('02 reg standard maybe).

But i'll look into the mod from land rover to make sure it is the one. Thanks.

Going from experience with headgaskets and thermostats.....
when the headgasket goes, you need to fit the uprated multilayer headgasket kit (complete with steel dowels). make sure you fit all the modified bits including the inlet manifold gasket. fit new modified nuts and threads to the inlet manifold. fit the modified thermostat and hose assy (goes directly from the radiator, thermostat is in the white plastic cylender) make sure you remove the old thermostat and DO NOT fit a new thermostat in its place! there is a blanking kit from landrover to replace the old thermostat assembly which you must fit. replace the expansion tank with the newer type 2001+ with the rachet cap that vents at 15psi. Have done this to mine and had no problems at all since!

frazzles, your posting contadicts it self, the new type thermostat is replaced as a complete item in its plastic housing, in place of the original thermostat is put a ring and seal for sealing purposes
if you had a drilled thermostat then you are running with old system, the hole makes good sense and is favoured by mgf k series fanatics,

Freelance, this was done before i aquired the vehicle (the hole in the thermostat). As the mechanic mentioned it wasn't good to do, i wanted some feedback and has been helpful so far.

By the way the mechanic has 30 years experience and has changed a gasket on a lot of k series in that time (i know him too which helps reduce the repair price lol). Not saying he is right, we can all be wrong but just wanted some feedback as to wether this was a good thing or not.

I'm still not drilling the thing anyway although wyldecyote's post about a blanking kit looks good if i can find it.

drilling it helps overcome the thermal shock when coolant is circulating, but the upgrade to to the relocated thermo unit does seem to be the right way to go.

and an EWP - that is critical to reduce cavitation after shut-down.

A remote stat, Pressure release stat and EWP all good, but your approaching the cost of hgf repair cost (parts only).

A drilled stat helps with thermal stress, nothing new, been done for years. Old school A-series engines have a hole with a ickle toggle valve.

Can't speak for the history of the OP vehicle, stat ring could have been drilled in the later stages and a load of radweld or k-seal chucked in??? Which has finally given up the ghost................ again

Can't speak for the repair history of the vehicle although the service history is up to date so at least the previous owner bothered to keep it in trim in some way. It's in good nick too so can't complain about that either.

Just bad luck it happened, if radweld or k-seal... unlucky . Never mind all sorted now anyway. Once again thanks for the responses, i was not expecting such quick replies.

When i bump into the mechanic again i will question him more as to why it's a bad idea to put a hole in the thermo, might have an interesting opinion. Will post here so you can slate him lol.