1999 lexus is200 V8 turbo (508BHP!!!!) For sale!!

Haha please don't say things like that. I'm not sure I've got it in me to take it out again 😂

Noted... I've actually made a bit of progress on this today. But il do a proper update tomorrow when it's "finished"

Cheers

Another update another cock up.. this is more like it. 1 step forward 15 back (it's cus I've mentioned the word Dyno) 🙈

So Monday morning fairly uneventful.. rad back in place with minimal drama.






So far so good. Dinner time rolled round and popped down to factors for a box of random bits. Including the new bottle, some 16mm heater hose to go to the bottle. New clips to replace owt I wasn't happy with. First thing I noticed. The mounting lugs are on the opposite side of what I really needed. Meaning I either needed to mount it back to front. Or the outlet will be on the wrong side.. it's also bigger than I thought it would be




Took a quick template of the mounting lugs before I set about plumbing the bottle in.figured I'd check it actually "worked" before I bothered making brackets and what not.




Reduced the pipe size from 19mm down to 16mm. Ran the lower outlet down to the pipe to the back of the water pump. And the upper outlet to the top of the rad as discussed.







Refilled the system (took a bit of lateral thinking since it was completely empty) but in no time I'd stopped getting any air out and only one thing for it. Time to try it. About this time my mate popped down and we like a noisy video so who am I to argue 😂



Ran it up to temp with the fan turned off. Got as far as 97/98 degrees and called it done. No leaks no steam and everything seems to be working well. Called it a day at that!

Today needed a bracket since I wasnt sure the paper would be strong enough. Settled on some 4mm plate which was definitely overkill. But I had some so make do n all that. The bottle doesn't really fit. It's not ideal but at this point I'm more form over fashion. I've only got so much space/time/ability..

Quickly roughed a shape out before cleaning it up with flap wheel n giving it a coat of paint (silver since it's all I had).. also sat it on some rubber to stop any risk of it vibrating and rubbing through.






Well that's it. It's in, it's secure and seems to work. "Insert smug face here"...

Decided to bring it home for one last "test" before the Dyno. Finished work in the sunshine, fired laptop up to keep an eye on things and set off..

Now it wouldn't be a proper test unless it got some wide open throttle enthusiastic driving (all within the speed limits of course). It also happened to be school run time so was busy til I got out into the sticks.. and with the odd check of the laptop it seemed happy.

A few wide open pulls on back lanes near me temp fine, running lovely and all of a sudden I lost the dash and it chucked a massive wobbly. Briefly cut out then restarted but missing. Dash doing whatever it pleased lit up like a Xmas tree.. "well done Mathew you absolute f****** idiot! What have you done now!?!?!

Pulled up to side of road opened bonnet (not really sure what to expect).




Top job coolant bottle "empty" and the Fuse box wet through. That will explain the wobbly. It's done this once before in one of its previous life's as a kettle when everything got drenched under bonnet!

Grabbed a rag, carefully took lid off and as pressure came off bottle it filled back up??!! Topped it off slightly (were talking basically nothing) rinsed the coolant off the car and carried on home.

Feeling slightly miffed got it in my head that it must need the top of the thermostat housing plumbing into the expansion bottle too (as per original set up lexus used)..

So tonight once I'd got kids down (Mrs is at work again) did what I've not done in a while.. went and worked in the dark on the drive..




Cut the pipe from the top of the rad and T'd in the pipe from the thermostat housing.. and how much coolant had I actually lost. After all that saga.. basically none. It was full 🙈



Did I need to T that pipe in. Probably not. Will it hurt anything. Doubtful. Will it "help"... Hopefully haha.

Buttoned it all up and not wanting a repeat of a coolant filled fuse box after I'd washed it out with contact cleaner (if it's over full again) rigged up a very very rough quick catch tank. So 1 I can see what it's pushed out. And 2 it doesn't spit dummy out if it does. If it's not pushed any out when I get to work tomorrow bottle can come off.



I've also had a quick look through the log I did just to check. And for the whole 19 minute it was logging it never once got hot. When I was stuck in traffic it briefly went up to 93/94 but soon as I started moving again it dropped back down to mid 80s! It was also mid 80s at the point it went wrong which makes me think it was over full more than anything. This is after several wide open pulls in 1/2/3. (Any more than that is just ridiculous)



Anyways. It's back together again. Is hopefully working. And if it behaves tomorrow on way to work. It's staying there til Dyno haha.

More soon!

Cheers

The blue cap is indeed a pressure cap (1.5 bar). The pipe for expansion from the top of rad/thermostat housing goes to the very top left of the bottle. The outlet back into the system is in the very bottom.

If I'm understanding right and the explanation a few pages back is right. The pressure goes into top of bottle and forces coolant down into the system..

The additional pipe I added last night is the overflow from the tank and only opens after 1.5 bar (it's a bit wierd how the set up works theres like a secondary chamber that the cap seals and allows pressure out once it makes more than set amount).. the pop bottle was just to catch any coolant that gets expellend incase I've overfilled the system.

Hope that makes some degree of sense

Cheers

Those VAG bottles are very tempting and available in a seemingly endless permutations of connections direction and mounting lug positions with and without level sensors and will and without overflow drains.

Be aware that the genuine pressure caps are quite pricey and many of the repro ones more than a little bit rubbish (as in not reliably holding or releasing at rated pressure).

It’s all “development”, I’m sure you’ll nail it in the end!

Nick

I think we're getting wires crossed.. least I hope we are.

Upper fitting on the bottle goes to top of rad (and T'd into back of thermostat housing were the factory bleed point is so must be highest/hottest point of engine)

Lower fitting goes to the pipe that returns to water pump. Last point in system so surely lowest pressure point?

That's how I understood what was explained. And more to the point thats how our factory is plumbed in. Lower outlet to bottom of engine to back of water pump. Upper outlet to top of rad?

Probably me mis-reading the diagrams then - as long as it works.

Btw, what's connected to the pipe on the right of the thermostat housing? The one that is low down behind the thermostat and hidden by your top radiator hose?

I've altered matrix pipes so it's down hill all way from bottle. Will have to do some figuring out when a matrix goes back in but for now it works..

Which pipe do you mean. The one that feeds the right hand side of thermostat comes up from oil cooler. The one that disappears under inlet just goes to q blank near where the bottle lives. It can be blanked at this end if it's all happy.

Cheers