2h oil pressure

Submitted: Saturday, Jan 03, 2004 at 00:26
ThreadID: 9460 Views:12092 Replies:7 FollowUps:11
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Can anyone tell if it is easy (I'm not a qualified Mech., but will have a go at most things) to fix the oil over pressure problems that occur with ageing 2h motors. I have heard if it gets really bad the oil filter canister can be blown clean off the motor.

Appreciate any advice
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Reply By: Member - Ross - Saturday, Jan 03, 2004 at 00:48

Saturday, Jan 03, 2004 at 00:48
Hi Ray

I'm not a mechanic by a country mile but oil pressure problems are usually low in nature due to the engine being shagged .... old life or whatever.

That being the case I can't see where you could blow the filter off, unless it was completely blocked and the oil pump was doing its job.

CheersFidei defensor

AnswerID: 41609

Reply By: V8troopie - Saturday, Jan 03, 2004 at 01:13

Saturday, Jan 03, 2004 at 01:13
Hi Ray,
I did have a 2H motor in my troopie which developed a very erratic oil pressure after about 170k kilometers. I was advised by a very reputable 4WD specialist that it was caused by wear in the pressure reliev valve piston/barrel. What's a new one I asked and was quoted several thousand dollars as the whole front housing had to come off to be either replaced or a sleeve machined for the pressure piston.
I opted for re powering with a bigger motor since I needed the extra grunt for towing anyway.
Leaving it as is was no option since diesel motors do require reliable oil pressure to run well, my 2H was dropping pressure badly most of the time when it started playing up rather than over pressure.
Bad news, these things playing up, I'm afraid.
AnswerID: 41612

Follow Up By: ray - Tuesday, Jan 06, 2004 at 23:46

Tuesday, Jan 06, 2004 at 23:46
thanks Klaus, what did you repower with petrol or diesel? and was it worth the money? I've been thinking about V8 diesel but I believe it can cost 20k's plus.
FollowupID: 304448

Follow Up By: V8troopie - Wednesday, Jan 07, 2004 at 02:29

Wednesday, Jan 07, 2004 at 02:29
Ray, I had a chevvie 6.2 litre diesel fitted for exchange of the old 2H motor plus 10 grand. Not cheap but worth it in my case as I tow a large boat ( 2.5t load) and the 2H struggled with that on the hills.
Also, I now can safely overtake in 5th gear, just step on it a little and off she goes.
FollowupID: 304460

Follow Up By: ray - Wednesday, Jan 07, 2004 at 22:52

Wednesday, Jan 07, 2004 at 22:52
That sounds pretty good Klaus, where did you have it done? what's the fuel consumption like?
FollowupID: 304600

Follow Up By: V8troopie - Thursday, Jan 08, 2004 at 01:53

Thursday, Jan 08, 2004 at 01:53
Ray, the conversion was done by Brunswick Motors in New Brunswick. They are a friendly mob to deal with, except perhaps the manager who suddely does not know you any more once you handed over your money. They did a pretty good job on my conversion, it took them only 3 days though they prefer one week I was told, even gave me a loan car for the period.
Fuel consumption is remarkable considering the V8 engine size, over two years averaged around 14 l / 100km town driving, up from the 13 l/ 100km the 2H motor used in similar driving.
Only long distance country driving I done since the conversion is towing a large boat, to places from Perth as far as Dampier and soon to South Australia. This obviously gobbles up more fuel but one can get away with around 16 l/ 100km if sticking to the 90k speed limit as required while towing the 2.5 ton load plus extra gear in the car and a dinghy on the roof rack.
FollowupID: 304625

Follow Up By: ray - Saturday, Jan 10, 2004 at 23:15

Saturday, Jan 10, 2004 at 23:15
Thanks klaus, I'm also surprised at that fuel consumption, alot better than you'd expect. Anyway I'll fix this pressure thing and keep dreaming about going V8!
FollowupID: 304940

Reply By: Paul - Saturday, Jan 03, 2004 at 02:00

Saturday, Jan 03, 2004 at 02:00
I bought a 81 petrol Cruiser that had a 83 2H put in it a couple of years ago. The engine control unit was disconnected because of the lack of wiring so I connected the oil sensor for the control unit to a red light on the dash.
I got worried that every time the engine had a good run the this light came on at idle so I pulled the sump of and measured the big ends and mains with Plastigage, they were well within the required tolerances and showed very little wear. I put new big and main bearings in cause I had the thing to pieces. The light still comes on but I don't worry about it anymore. From the dates on the bearings the engine must have got a complete overhaul in about 1994 as they were marked June 1993. I reckon as long as you change the oil regularly the old 2H will go for ever.
AnswerID: 41615

Follow Up By: ray - Wednesday, Jan 07, 2004 at 00:00

Wednesday, Jan 07, 2004 at 00:00
thanks Paul, This high oil pressure is a common happening according to a few 4wd mech's that I've been talking to, it'll either blow the filter clean off the motor or split it open down the side of the filter canister. It happens at 300k+, regardless of maintaince. I always change my oil at 5k's including filter and reckon its cheap insurance. Would you know where I could geta genuine engine workshop manual, toyota dont sell'em any more.
Regards Ray
FollowupID: 304451

Reply By: Dave from Fraser Coast 4WD Club - Saturday, Jan 03, 2004 at 08:10

Saturday, Jan 03, 2004 at 08:10
I've never heard of them suffering from over pressure, I was having an underpressure problem at low revs, but that was simply a retun line (inside the block) that had come loose, and was a very easy fix.
AnswerID: 41620

Reply By: Phil G - Saturday, Jan 03, 2004 at 10:48

Saturday, Jan 03, 2004 at 10:48
Most of the "low oil pressure problems" on 2H and 12H-T's were a problem with the sender unit going out of calibration with time. I replaced the sender once and the gauge read normally again, and later on when it began reading low again, didn't bother about it.

I'd love to have a dollar for every 2H motor that has had major mechanical work because the sender has gone out of calibration.
AnswerID: 41631

Follow Up By: ray - Wednesday, Jan 07, 2004 at 00:03

Wednesday, Jan 07, 2004 at 00:03
Thanks for that Phil, the pressure drops off when it gets hot but I didn't realise the gauges can play up as well!
Regards Ray
FollowupID: 304452

Reply By: brownie - Saturday, Jan 03, 2004 at 11:10

Saturday, Jan 03, 2004 at 11:10
Ray, I've had the over pressure problem with the 2h motor, and yes it DOES blow the filter off !!
The problem is the oil pressure relief valve at the front of the motor - it wears a little groove in the housing & then jams up. A new valve piston fixed the problem for me, but if this doesn't work then you can either buy a new housing (for mega$) or perhaps get a slightly longer valve piston machined up - this will stop the piston jamming on the groove in the housing.
Regards , Brownie
AnswerID: 41633

Follow Up By: ray - Tuesday, Jan 06, 2004 at 23:51

Tuesday, Jan 06, 2004 at 23:51
Cheers Brownie, I'm glad that someone believes me about overpressure
problems, did you do the work yourself?, I've since been told its not all that difficult, it's just underneath the power steering pump no need to rremove the timing case or anything else.
regards ray
FollowupID: 304449

Follow Up By: brownie - Wednesday, Jan 07, 2004 at 01:26

Wednesday, Jan 07, 2004 at 01:26
It's not a big job, I think a new piston & spring was about $10, from memory I used the old spring with the new piston - seemed to work ok on my engine.
I had 2 filters blow apart - very messy & inconvenient. My low oil pressure cut out switch did its job & killed the motor before any damage was caused - hope yours works too !!

Cheers from Brownie
FollowupID: 304457

Follow Up By: ray - Wednesday, Jan 07, 2004 at 22:56

Wednesday, Jan 07, 2004 at 22:56
Thanks Brownie, yeah my cut out switch works, so I just need to order a new spring and piston.
FollowupID: 304601

Reply By: Nav 80 - Saturday, Jan 03, 2004 at 13:03

Saturday, Jan 03, 2004 at 13:03
Gday Ray,,,The oil pressure relief valve as allready mentioned is very easy to remove. If you get under the front of the vehicle you will see just under the front crank pully a large nut, from memory I think it is about 24mm faceing out to the driver side of the engine. If you undo this nut you can pull out the spring and piston. There is a set length the spring should be but unfortunatly I cant remember what it is but it is listed in the Toyota workshop manual. Check to see that the piston slides freely in its place and replce the spring with a new one. If the piston is sticky,as mentioned it is not so simple and this indicates over pressure. If the pressure is low it indicates the spring is week and a new spring should do the trick. Another problem this valve causes if the spring is week is low brake vacum as the vanes in the vacum pump rely on oil pressure to push them out and seal.
AnswerID: 41640

Follow Up By: ray - Wednesday, Jan 07, 2004 at 00:11

Wednesday, Jan 07, 2004 at 00:11
Thanks NAV 80, it seems I've got the idea how to fix it now, however one mech said he pulls the piston out, and if the bore is a bit rough uses very fine wet n dry wrapped around a pencil and gives it a quick rebore, and then stuffs in a new piston,,,,,, you'd think it would make the prob worse!

Regards Ray
FollowupID: 304454

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