Paul TVR

I've just fitted my secondhand greddy kit to my car, I bought a breaker MX5 and took the turbo off, I test drove the car for some time, all seemed well with the kit, then started the swap over.

I pulled my engine, replaced the sump with the one that had the oil feed, now I have assembled the engine again, I took the car out, I noticed the oil pressure gauge reads max 6 on the dashboard gauge when revving, and drops to 4( just over halfway) when idling. on my first run the turbo has blown the oil seals, there is lots of smoke and the pipework is full of oil.

Very fed up, starting to wish I never started this project!

psiturbo

iTrader: (1)

Did you see the other thread about 2 blown turbos in 3 months, there is a picture of the restrictor you must have on the oil feed line.

Is it a mechanical oil pressure gauge?

I read somewhere a guy states or you really know what you are doing or you dont no anything at all. On turbo projects there is no such thing as I have an idea of what I am doing, either you got it or you don't.

Do you have pictures of your setup, engine bay?

Are you saying 6 psi of oil pressure? Or is it one of those gauges (similar to the tach) that says 1,2,3,4,5 and at the center has a x 10 meaning it is really 60 instead of 6.

If it was "really" 6 psi I would not have even driven the vehicle.

Paul TVR

Ok, I have a the standard dash gauge which is in kg/cm2 so using a converter that means approx 56psi at idle and and 85psi under load. This is of course if the pressure gauge is any good.

Photo of the set up, the pipe for the oil feed didn't appear to have a restrictor as far as I can tell, its just a braided pipe with a banjo fitting at the end.

Paul

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psiturbo

iTrader: (1)

Your mechanical oil pressure gauge seems to be working fine, your engine would have seized long time ago, in fact it seems a very healthy engine with such high pressure. I would try a lower viscocity oil next time, maybe a 5-30W, I prefer regular motor oil than the infamous synthetic, and/or maybe you had too much oil on the engine and pressure readings are higher as normal (thats if your conversions are correct).

I experienced the same issues as yours many years ago the first time I did my turbo setup. Did exactly like you, hooked it up without a restrictor and the turbo seals went through the roof. For example, my restrictor on the china egay turbo T3/T4 delivers 15 psi. On the other thread there is a picture of the oil feed restrictor, no need to open it up anymore than it is.

I think if it is a ball bearing turbo the pressure can be lower, but is another subject and has nothing to do with your problem. If you did not have a restrictor then that is the reason the seals blew up, 50 to 80 psi is way too much pressure for those small seals.

I do not recall now how much they cost on egay, I bought two back in then when I did my setup, the ones from egay are as good as the ones sold in any turbo store.

By the way, the engine bay looks sweet and must give you props on how the turbo looks clean and nicely done, too bad you had that incident with the seals.


Like the yellow hoses and red piping! Excellent job on tha valve cover!

Note: So nice of turbo setup, get rid of those worm clamps.

Paul TVR

Thanks, I will try and get a restrictor. how do you measure the oil pressure at the turbo, will check my banjo fitting and see if it is a restrictor type, also wondering if the oil could have got too hot, I noticed I brought the oil through the exhaust manifold, but on the car it was take off the oil feed came up the front of the turbo, could the oil being too hot effect the seals?

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The colour choice was like that one the car I bought, also had the polished cover and intake, so I've taken those for my car, the other one used a awful lot of yellow pipe everywhere though which I thought was OTT.

This is the car it was taken from

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What's wrong with the jubilee clips?

Paul

Braineack

iTrader: (62)

the greddy lines do not need a restrictor....nor can you really fit one on a banjo fitting for that matter.


smoke will be normal on first start-up, you gotta burn off all the crude and oils from touching the hot parts. Where is the oil showing up in your pipes?

Paul TVR

smoke was ok, passed the MOT test etc, took it for a run it started to pour smoke out the exhaust, it was James Bond style couldn't see anything behind me type smoke.

I took the red U bend pipe off, that comes out the turbo, where the step of the yellow pipe joins the turbo outlet there was a puddle of oil.

psiturbo

iTrader: (1)

Ah well, you got me there about the Greddy oil lines that are different.

Braineack, so the oil feed lines supplied with that kit already have the restrictions?

No, smoke WILL NOT be normal on the first startup, I did not see a drop of oil whatsoever and mine was a EBAY universalt kit. Maybe black smoke if you went to rich on the adjustable fuel pressure regulator, but white blueish smoke, naah, that is not a good sign at all.

One way to measure pressure would be to have custome made T, just talk to any hydraulic shop let them splice it and make the fittings so a oil gauge can be adapted. I do not have a gauge on the oil feed line, mine is routed inside the vehicle cabin, typical autometer mechanical one (like 40 bucks or so). How I know it is 15 psi?, because it says it on the paperwork when I got the fitting from EBAY, the size is somewhat standard, and it explains which other bits you must use to open it and how much pressure depending on the size, no need to mess with it so I installed exactly how it arrived.

Note: you mention the kit came from another vehicle, are you sure it was in good condition when you bought the car?

Paul TVR

The kit was running fine on the other car,one thing I did notice about the other car though was low oil pressure and a slightly knocking bottom end when cold.

I will get myself a proper oil pressure gauge, might even have one in the garage actually.

Paul

Bryce

iTrader: (24)

Is the oil return line all downhill? If it is not allowed to drain properly you can blow the seals.

The stock Greddy oil line doesn't use or need a restrictor, as Brain says.

Braineack

iTrader: (62)

Starting to think the turbo needs a rebuild, how's the play on the wheel?

If it's not that, your PCV is completely failed and letting boost push oil back through the intake pipe. if you can blow through the pcv valve you need to replace it.

If that's not it, your oil drain is to blame. If there is any uphill travel the oil cannot drain out of the turbo fast enough and it'll push out the turbo seals. How is your oil drain routed? The long as hose around the left side of the motor to the stock port?

if that's not it, you toasted your rings.

No, but it's a small -3an line (already something like 50% less flow area over a -4an) and the banjo fitting has a very small inlet on the bolt. This site was derived from a Greddy specific miata turbo site, "general chat" used to be "greddy chat". have yet to hear of any greddy kit needing less oil pressure.

yes it will, there's paint that will burn off, grease from your hands, random **** inside pipes...there should always be a little smoke under the hood and out the tailpipes when you first fit a kit.

^^^ this.

sixshooter

iTrader: (12)

To answer your question, the worm gear clamps will fail at higher pressures. T-bolt designs are more commonly used for that reason.

The vent hose from the valve cover might be some of your oil problem. The area it is plumbed to in front of the turbine is in a light state of vacuum because you have the AFM and air filter upstream of it. This may be causing some amount of oil to be drawn in. You might consider a catch can (or overflow) type arrangement that would allow the liquids to settle, but still return the gasses to that inlet. Turbo engines tend to develop more "blow-by" because of of the increased cylinder pressures. Newly rebuilt or older engines also are more susceptible.

Also +1 what Brain said. Sometimes a little oil smoke is ok when you are just getting it going, but it should go away within 5 minutes as everything gets really hot.

Your oil pressure appears to be in the high-normal range. I would love to have oil pressure that strong.

I also would have immediately said oil restrictor and then oil drain line as well, but that has already been covered. If there is still an outside chance that the oil feed line is not an original Greddy unit, but a replacement unit, then the old engine's oil pressure might not have been enough to overload the turbo seals, but the new engine's robust pressure might have been more than they could handle.

Paul TVR

I'm not sure if the oil feed is the standard Greddy one, the banjo fitting looks like this

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so quite a reasonable size hole, the oil return fits like this then drains straight down into the sump

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The puddle of oil

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The kit never had the crankcase vent connected when I bought the other car so I left this blocked off, so the only way oil is getting there is from the oil supply to the turbo.

So looks like I will be buying a rebuild kit, is it worth getting a restrictor as well to be safe? I presume once the seals have leaked they will need replacing so simply fitting the restrictor wouldn't cure the problem anyway?

Braineack

iTrader: (62)

correct, a restrictor will only cure oil pressure related smoking/blow-by issues.

you might try replacing that S-bend hose (which will ultimately fail from heat) with a longer length of good heater hose that will softly corkscrew down, that might still be the issue.

sixshooter

iTrader: (12)

You do need to vent the crankcase at the valve cover either to the atmosphere or to the compressor inlet pipe. Otherwise your crankcase will pressurize and your engine will leak and blow seals.

Braineack

iTrader: (62)

yes, if anything just leave the breather port open, but it should be plumbed back into the intake pipe (pre-turbo)

Paul TVR

It is venting to air at the moment, but I left the block in the intake pipe to stop a air leak.

I've got myself some heater pipe and plumbed that in to see if it helps

Will see what happens next, I'll order a rebuild kit for the turbo... will be my first time stripping down a turbo, wish me luck

Braineack

iTrader: (62)

get yourself a good pair of snap ring pliers.

TrickerZ

iTrader: (6)

I need a pair of snap ring pliers too. Any recommendations on what to get? I keep finding ones that are too small to pull the compressor housing snap ring off.

Paul TVR

Well, I fitted a new hose, also moved the oil feed away from the inlet manifold, I know my TVR had problems melting the engine mounts as the support bar went through the manifold and radiated heat caused the bar to heat and melt the mounts, thoguht as the manifold gets very hot route it away and over the heat shield, So thinking the oil maybe very hot and getting too thin.

Took the car for a drive, there was some smoke still at first, but seemed to clear and now seems much better, I can't see too well as its dark and wet here in London but its clearly not like it was yesterday when drove it.