Outer Limits 4x4 Board

1985 troopie all off sudden oil pressure is fine when first starts then gauge drops to zero, who can tell me where to start to find problem, thanks

Start by hooking up a test guage to rule out an electrical problem with the gauge system, and to confirm you actually have no pressure.

Does the oil light come on too?

X2 on the guage mate

x3 in mechanical guage.

Does the engine cut out at all?

If it isnt the guage, start by looking at the oil pressure relief valve located on the timing case, bottom drivers side. Big nut, about 24mm? with a spring and plunger inside it.

These are very well known to give problems in 2H's and 12HT's as they often stick shut, causing massive oil pressure (150+PSI, POP goes the filter!) or stuck open causing piss all oil pressure. On my 2H it was sticking shut which caused 2 messy messy filter blow outs.

To get the plunger out, you can either take your PS pump off (as i did the first 2-3 times) or just turn the car over for about 2-3 seconds. Its messy so put some drop sheets down and obviously you dont want to let the car start cause it will spew a sump full of oil all over your tire in about 30 seconds!

Then you want to get a new plunger. About $10 from toyota. Also clean the bore of the relief valve out. I used 5-56 and a rag on a stick (simpsons?).

Mine had a significant step in the bore which I used some dowl and wet and dry to linish a bit.

You can also get an aftermarket plunger which is about 10mm longer and seems to fix the problem for alot of people. These are usually about $30!!! (but a new timing case is about $300 from toyota, plus then youve gotta put it on!)

That's some really good tech there shadow.

on start up it used to switch off after a few seconds then second time round all fine, no i haven't seen an oil light come on (didn't think it had one).thanks guys for feed back.

fairly certan there is no oillight in the 75s, i never had one come on in 5 filter blowouts.

what shadow said is good, go to a wrecker or parts place for the longer relive valve. (toyhatsu has them) i didnt take my power steer off, i just went to super cheep, bought a cheep spanner and cut it in half and un done the bolt that way, with out the trip to super cheep in the middle the job took me all of 10 mins.

thanks for advice ,can anyone tell me where i can buy a longer oil pressure relief valve

stan wrote:thanks for advice ,can anyone tell me where i can buy a longer oil pressure relief valve

I've seen them on ebay, but havent looked for a while.

also QLD Diesel Spares carry them.

toyhatsu in tottenham vic, sure they can ship it

thanks ,managed to get one from sunstate 4x4 kerry rd archefield.cheers

Hi sorry to hijack but did the new valve stop the car from turning off again on startup as my 2h has always done it and would like to fix it

thanks Shane Mulcahy

my 2 h never really had that issue. although if i dont glow the motor twice and then push the pedal to idle at around 1000rpm for the first few seconds it will be rough and stop, but once its ive done that it idels fine at 500rpm. i dunno if that will help you or not though

Mulcahy wrote:Hi sorry to hijack but did the new valve stop the car from turning off again on startup as my 2h has always done it and would like to fix it

thanks Shane Mulcahy

Not sure actually.

havn't had time to work on it as yet ,will over weekend and keep you posted

replaced,oil relief value.(much longer plunger and new spring+honed out cylinder)have the same problem no change,when starts up oil pressure is fine then no oil pressure at all.

stupid question where is the oil pressure switch that sends reading to guage in dash on a 2h..

mines right under the intake manifold, around number four or five cylinder, bout halfway down the block, its a round unit about two inches wide, it just unscrews from the block

stan wrote:stupid question where is the oil pressure switch that sends reading to guage in dash on a 2h..

I think the auto shutdown is switched off a different pressure sender to that of the gauge. Same side of the block, smaller sensor iirc.

thanks dexter,

ok. longer plunger in oil pressure relief valve does work,oil pressure comes up much quicker thus engine doesn't stall,hope that helps anyone,problem fixed thanks everyone cheers...

stan wrote:ok. longer plunger in oil pressure relief valve does work,oil pressure comes up much quicker thus engine doesn't stall,hope that helps anyone,problem fixed thanks everyone cheers...

awesome result mate.

stan wrote:ok. longer plunger in oil pressure relief valve does work,oil pressure comes up much quicker thus engine doesn't stall,hope that helps anyone,problem fixed thanks everyone cheers...

hopefully it will be the same fix on my 2h troopie