Rebuild questions of the 1hz

[sam89]

Hi all i am a new member and am currently in the process of buying a 105 series. I stumbled across an add for one (1999 105 with 480xxxkm) that has had alot of money spent on everything imaginable and the car is immaculate. however it has just had a full rebuild (50km on clock since) lots of money spent but i am unsure how reliable re built motors are? the owner seems like a very reasonable guy and took me to the workshop who assembled the motor aswell as there is a 12month transferable warranty. the only reason he is selling is he doesnt use it as a 4x4 anymore is quite well off and doesnt wanna see it go to waste. I am just not 100% on how reliable and how much life i will get out of the rebuild.

the owner had the rebuild done with a full turbo kit i.e pistons, rings all set up to run the aftermarket turbo (gturbo badboy extreme) fitted. the boost has been re calibrated to 10psi and the 12mm pump had also been calibrated back to factory specs for the run in process.

i have no doubt he has done everything correctly i just want some honest opinions on buying rebuilt 1hz motors

cheers for any advice thanks, sam

 

[clivehorridge]

Welcome aboard Sam and your 105

It’s impossible to say when none of us (including you) really know what’s gone on in the process of this rebuild, but the 1HZ is bomb-proof as you may already know.

Mine’s on 412k kms and although a bit rattle, it pulls like train and has never failed me in 12 years...

I’m also considering a turbo but it wont be pistons as well, just an add-on. A turbo fitted to a standard 1HZ needs to be done with some care and to bear in mind that it shouldn’t be boosted too high. Otherwise, they respond nicely to some extra air, a mat of mine has had one fitted to his for the last 2 years, and he has no problems, even without a piston upgrade.

If I were you, I’d relax keep it all well serviced and enjoy the ride for the next 1,000,000 kms.

 

[sam89]

cheers clive,

yeah the reason for original failure according to the owner was that the turbo was registering only 14psi on a gauge which must have been leaking or something i guess but actually making 27psi which put a rod straight through the crank (i have seen the old crank) so i know its got brand new crank rods and pistons, the whole head is brand new also. all the work done was at apretty reputable engineering company in gold coast australia also.

thanks for the reassurance, i am slightly paranoid as i previously owned a hilux that cost me a small fortune as i bought it with almost failed injectors and 220,000km wound back on the clock so i definitely learnt my lesson to do some research these days.

cheers sam

 

[clivehorridge]

cheers clive,

yeah the reason for original failure according to the owner was that the turbo was registering only 14psi on a gauge which must have been leaking or something i guess but actually making 27psi which put a rod straight through the crank (i have seen the old crank) so i know its got brand new crank rods and pistons, the whole head is brand new also. all the work done was at apretty reputable engineering company in gold coast australia also.

thanks for the reassurance, i am slightly paranoid as i previously owned a hilux that cost me a small fortune as i bought it with almost failed injectors and 220,000km wound back on the clock so i definitely learnt my lesson to do some research these days.

cheers sam

I’m not surprise it blew the top through the bottom. That rebuild must have set him back almost the value of the truck.

Just run it in nicely and it will be a good ‘un I’m sure.

 

[Nathan Busteed]

Watch the R151 box that the 1hz trucks come with. Once turbo-ed, they are notorious for popping second and fifth gears. Judging by the $ it sounds like hes spent, he may have already converted to a H151

 

[sam89]

Yeah so ive managed to get alot of info on it since my last post as it has been at the workshop for the majority of the last 6 months. I have actually become mates with the apprentice at the shop and he told me the truth about the car/rebuild.
The original rebuild was done with top quality gear and the owner put the h151 fully rebuilt in and thought it was a good idea to run it straight after rebuild at 30psi and with no oil in the gearbox due to hus ignorance which obviously ruined everything. So it has been rebuilt twice now the box that is in it now is a second hand r151 with god knows how many kms and the second rebuild kit was a cheaply cause the owner just decided to cut his losses. But ge also sold it as the upgraded box and told me the money he spent to rebuild it was the kit that it is currently running which is not the case. Its had seals go almosy weekly stretched head bolts and all sorts of dramas. Along with finding that they had decided to hook the boost compensator up to the vacuum pump for te idle up cause they were so paranoid the kit was rubbish.
Its now been switched back and have tuned the pump which has made it run much nicer at 15psi and egts no higher than 380c
So does anyone know where i can pick up a h151 in Brisbane area?

 

[sam89]

Well the 1hz lasted 9 months and 7000kms before it blew up again. Along with having a leaking engine block due to apparently not being crack tested during rebuild process. Which caused some overheating and damaged pistons and valves. I am now in process of converting to a 1hd-t cause my faith in the engine builder and motor is now zero. Back to square one and broke as

 

[StarCruiser]

Oh heck Sam, that is bad news indeed. Sounds like a good plan though and you won’t regret the extra grunt from the 1hd-t. I expect you’ll try and get one with history that you see running but guess that may not be easy.

Good luck with it and keep us updated as to how you get on. Even post up for an engine, you never know you might get lucky. There is one for sale but it’s half way round the world so I think you’ll get one closer otherwise you could look into shipping I suppose.

 

[StarCruiser]

Well the 1hz lasted 9 months and 7000kms before it blew up again. Along with having a leaking engine block due to apparently not being crack tested during rebuild process. Which caused some overheating and damaged pistons and valves. I am now in process of converting to a 1hd-t cause my faith in the engine builder and motor is now zero. Back to square one and broke as

What about the 12month transferable warranty? I’m guessing that hasn’t panned out like you hoped?

 

[clivehorridge]

Ouch

 

[sam89]

Yeah i have found a bloke close to where i am located that specializes in the 1hd family of motors and is building me one up as we speak with all the good stuff. The warranty is still in question as the previous engine builder didint want to touch the engine block his solutions was for me to drive 3hrs for him to put some stop leak in the radiator which i was pissed off about to say the least. It obviously didnt stop the leak and he said to just wait as it may take a few weeks for the stop leak to work its way into the cracks. It was in that few weeks that it failed as it was still experiencing overheating even on small drives and eventually failed. I have offered two solutions to him, the first being he can pay for half the price of the 1hdt and that is all no parts no labour and ill be happy. Or he can supply a tested 1hz block and rebuild it again at his cost. He has refused either option and has said he will grind out and fill cracks and fix the piston/valve problem as well but i have no faith in a motor that hasnt been crack tested which he has admitted to so i will be going through fair trade and getting an independent assessment done on the motor once removed.
Thanks for the reply, ill keep you posted with the new build and upload some photos as the crack is getting balanced as we speak and the pistons are getting ceramic coated so ill send some photos once that is all complete

 

[StarCruiser]

The better pistons have steel lands which is the only internal modification done by Yanmar when they build the marine version that gets over 300 bhp. The rest is external and utilises the massive cooling available from the water.

 

[sam89]

Yeah i have heard the yanmar variants make some big power. Im pretty excited to drive the 1hdt its getting whole bottom end balance done ceramic coated pistons, gturbo grunter extreme, pwr radiator and fmic all put on aswell. Just worried the box will be the next to die. Im not sure which rebuild kit the new engine builder has gone with though but i am hoping it lasts longer than the 1hz

 

[StarCruiser]

Toyota only at that level I would say.