Finally took my turbo mini for its first drive BUT
Turbo Mini Forums

Well iv got my turbo mini on the road now and took it for its first drive today.

When i first start the engine up i get just over 50psi oil pressure, if i leave it idling for about 15 minutes the pressure drops to around 25psi.

BUT when i went for a drive today, after a while i checked the oil pressure and realized i was only at 25psi under load, and when i took it out of gear it dropped to about 10psi-15psi.....

Now iv never played with turbo minis before only N/A and i wouldnt want this in an NA engine atall, does the same apply for turbo?

This is that same engine that i had running before i converted it to turbo and at idle when hot the oil pressure would be about 35psi... so i can only suspect the extra pressure can be taken up in the turbo?

Has anyone got any thoughts on a solution.

Initially i suspected the mains must be worn, but why did this not show in the engine before?

yes you are correct, the rule apply`s in all engine`s, i see around 27psi idle and 55/60psi when in drive. when was your engine last rebuilt?

mine does this too,

i set it to 80psi in cold at idle
when its warm it drops to about 40-50
but when its been ragged for a while it drops to 20-30..

i thought it dropped off cause the oil was getting too hot

Did you uprate your oil pump?

If yours was a little worn then maybe its struggling to keep up now its feeding the turbo aswell.

As said above, if the oil is getting too hot then your oil pressure will drop. I wouldn't expect it to get that low mind.

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1/4mile in 13.2sec @ 111 terminal on 15psi

Not sure when it was last re-built, but was just a bit surprised as it had ok oil pressure before the turbo conversion was done.

Yes i fitted a new turbo oil pump.

Is there a way i can raise the engines oil pressure? As i know you can drop the oil pressure by cutting the pressure relief spring down...

Edited by tomf on 8th May, 2010.

Put a washer in between pressure relief 'cap' and spring (effectively lengthening the spring).

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1/4mile in 13.2sec @ 111 terminal on 15psi

pack out the pressure relief spring with washers behind

Perfect, ill have a play with some washers next time i get the chance, then hopefully that will solve my problem.

this is normall with a worn engine

change the oil to 20/50 and add a can of STP its evident that there is a slight worn oil pump and also the shells

check and make sure the relife valve is not stuck off its seat a tad! with gear steel ..... this does happen sometimes

i wouldnt worry about it if the engines done a few miles

i would measure the free length othe relife valve spring and compare the measurments to the haynes manual .... i think ? 73 mm rings a bell
hope this helps

Thanks benross, its already running on halfords 20/50 oil and its got a brand new minispares turbo oil pump fitted. I guess the shells could be a bit worn, but they same shells gave alot bettor oil pressure with the non turbo pump and turbo parts added...

I take it STP it sort of a oil thickener? ill google it after i reply.

Ill get the relief valve out asap and check to see if its stuck at all ill also measure the spring to see if its worn out.

When i come to add some washers to pack out the spring, i take it this is just going to be trial and error or is there some sort of ratio to work of?

Just trial and error mate.

As benross says its worth checking for signs of the shuttle sticking.

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1/4mile in 13.2sec @ 111 terminal on 15psi

If it's any help to your situation, I also recently changed the oil in the mayfair to the halfords 20W50 stuff, and found that it has burnt more than half of it off over a period of about 8 months!

In comparison to the oil it had in it before which is unkown to me as it had that oil when i bought it, but none the less, it had never burnt a single drop of that over a period of over a year.

The engine has done about 85k miles and never leaks a drop.

Whether this highlights any issues with the halfords oil itself, i'm not sure, but it seems that way.

Ok well im now very confused.

I took the spring out and it measures 72mm, so i set about spacing the spring, so at first i tried two small washers in to the dome nut, thus lengthening the spring, and this didnt make much different, do i removed the nut and added a couple more washers, this brought the initial cold idle up a little bit to say about 55-60psi.

So i took the dome nut off again and added a few more washers, at this point, there is only enough room for the end of the spring to locate, so the nut is near enough full of washers.

The cold idle pressure was still only at about 55-60psi though, but when i blipped the throttle it would raise to around 75-80psi.

So i took it for a 10 minute drive to find the oil pressure dropped back to about 25psi under load and about 10psi when left to idle out of gear...

Anyone got any thoughts, i really havent got the time at the moment to strip the engine down again, but its looking like thats the way things are going :(

Shells are fooked.

i agree with Tom my clubby does similar, its over 95k on the engine frequent oil changes keeps the pressure up, about 2000 miles and the pressures are almost zero after a good motorway pull

it needs fixing properly, at minimum crank grind and shells imo

Yes i moved to the darkside

Instagram @jdm_brett

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Usually scoring. There may be some debris hanging about.

One way of getting it out is to find a piece of dowel that will fit snuggly in the back of the plunger and then draw it out.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yes i moved to the darkside

Instagram @jdm_brett

Paul hopefully you are correct, iv just removed the plunger (fridge magnets do have there uses sometimes haha)

Well now the plunger is out i can see its got scoring all the way round, so hopefully it has been sticking and a new plunger will solve the problem a little bit, but time will tell.

Brett, thats good to know as it means ill be able to strip the engine down if the plunger doesnt solve my problem when i get the chance.

Also would you say its best to stick with the plunger type or swap to the ball?

ive always used balls...

oh balls

The plungers are good at sticking with the slighest bit of debris, if you change to a ball make sure you change the spring too as the ball spring is a different length.