1.6 TD JX Oil Pressure

[torchy]

I've had this [following] topic on Technical but no answers forthcoming, I'll now put it here as I think Syncro owners are maybe more mechanically minded? Hope someone can help because I'm missing out on away days, It failed on the way to Coney and I missed syncropendance also, hopefully will make the next Devon outing. Fingers crossed...Help!

I've got a crew cab 16" Syncro with a 1.6 TD JX Engine with oil pressure problems.

Twice I have been towed back by the RAC because the oil pressure light and buzzer was on, and have now at last fitted an oil pressure gauge.

When starting from cold pressure is just under 1 bar, rev it up and no difference just stays at about 1 bar!. Leave it idling to get nice and hot, the pressure drops to around 0.5 bar (ish...on the gauge)...A bit close to the 0.3 bar oil pressure warning light/buzzer which duly makes an appearance. No matter how much I rev it it does not go above about 0.8 bar......and I've just fitted a Baxter oil cooler (in case it's mentioned).

My 14" MV petrol has an oil pressure relief valve, but according to my bently manual I can't see one for the JX but it must have one, surely??? Does it??

It's suppossed to be a new engine and certainly looks like it, I've got receipts from Patrik in Sweden that say's it is although now wondering if it was maybe just the head, the block is not so shiney after all

I've been told to try a new oil pump.... OK ...but if it doesn't solve the problem thats a big waste of money and this truck is already mounting up some serious repair bills (re above RAC!!)

I dropped the bash plate etc off tonight and over the weekend will drop the sump for a gander, What do I look for??

Any help/advice gratefully accepted.

[PC52]

The answer is:
it's retired, 20+ yrs old, that poor little JX has done all the work it can do.
Give your doka a new lease of life AAZ or push the boat out and mTDI

[lloydy]

Mines an AAZ, but as a reference from cold start my pressure is just shy of 80psi, now if my maths is correct is 5 ish bar. At hot idle it's 20 odd psi, which is 1.5 bar? And at about 4000rpm on the motorway I'm again just shy of 80psi
Stop spending money on it and get an AAZ, when I scrapped my jx I got nearly £500 for the bits, and only paid £200 for the AAZ

[syncropaddy]

Renew the oil pump and filter and use a good oil like Castrol Magnatec. If that doesn't work then put in an AAZ !!

[..lee..]

if your dropping the sump off be silly not to check the crank bearings while your in there

[HarryMann]

So sorry to hear that story Peter, quite a few of us have been there before, and it can get very frustrating

Yes, there is a pressure relief valve, or should be one.

What you should ask or find out is what exactly the history and work done on this engine is?

You say nothing about the turbo, if it is smoky or suspect in any way, block off the oil feed and see what pressure you get at idle, they can pi55 oil past their seals as I've found, frequently ignored in oil pressure discussions. (Of course don't run under power with no oil to the turbo).

Even if it is new(ish) the oil pump but more likely the JX oil pickup extension is the original one. Sometimes, one finds some very strange things that have been done, or not done, during rebuilds...
The first to check would be the pickup screen (quite small), having found very strange items before, and whether it is fitted correctly. Then the pressure relief valve, which I think is in the pump. Never been a great believer that pump wear on these make much difference, unless it appears physically damaged rather than just worn.


Those are strange symptons, something is very wrong (but lets talk about driving at speed and a given steady rpm, not this 'revving up' ). Always let a VW diesel sit at idle for a good few seconds after starting they are not known for retaining oil in the galleries overnight, or after a few days.
Seems you are saying even when cold pressure does not increase roughly proportional to revrate?

=========================================================
Are you saying that at speed you get little over 1 bar (not interested in revving up, steady speed)

Mine is new VW short engine, (AAZ) and if the gauge is to be believed, a rule of thumb is as follows:

One bar per 1,000 rpm when hot (80 C)

900 rpm idle when hot about .75, sometimes 0.5, don't worry about that too much, what matters is either side of 2000 rpm the pressure conforms to VW's DOPWS norms.

Have never seen Lloydy level pressures on an IDI VW engine, but others do, which I find strange itself.
===============================================

All this presumes you drained and checked the oil for debris, coarse and fine, and she has a new filter.

Good luck keep us posted.

[HarryMann]

Oh yes, you can check the BE shells, but not all the main bearings with the sump off/engine in.

Low oil pressure on these engines can be intermediate shaft and the top-end condition (camshaft bearings)

... but the way you describe it, the normal observation of good and apparently OK when cold, rapidly deteriorating as oil temp approaches 80 ~ 100C, is not what I am hearing in your introductory post.

[Simon Baxter]

Put it out of it's misery, put a AAZ in.

[torchy]

Oh yes, you can check the BE shells, but not all the main bearings with the sump off/engine in.

Low oil pressure on these engines can be intermediate shaft and the top-end condition (camshaft bearings)

... but the way you describe it, the normal observation of good and apparently OK when cold, rapidly deteriorating as oil temp approaches 80 ~ 100C, is not what I am hearing in your introductory post.

This is the anomally, Cold.. OR.. hot it will not go above around 1 bar, even when I bring up and hold the revs, also it's a brand new Turbo from Baxter, so I hope I can fix it!

So This weekend it's:

• Drop the sump
  extract the pump
  check the suction tube and non return valve
  inspect the BE
  Inspect any Mains possible
  Lift rocer cover and inspect the cam bearing (if I can)

If all appears OK I'll order a new pump through the week.

I'm going to try filling with "Mobil 1 Extended Life 10W-60" it's viscosity at 100 degrees C is the best of any oil at 22.7 cSt and apparantly tolerant upto 160 degreees C. Any one tried it?? Apparantly "engineered for the specific demands of older vehicles"....

Thanks everyone for their input, I'll report back!

.....and what's so good about an AAZ anyway??

[HarryMann]

I'm going to try filling with "Mobil 1 Extended Life 10W-60" it's viscosity at 100 degrees C is the best of any oil at 22.7 cSt and apparantly tolerant upto 160 degreees C. Any one tried it?? Apparantly "engineered for the specific demands of older vehicles"....

Sounds great stuff, but in this instance Peter will not make any difference other than to your wallet. Wait until you have found the problem...

I expect you will find something strange with the pickup screen, thats a strange sympton

[Simon Baxter]

I bet the intermediate shaft Bearings have broken up.

[torchy]

This is what I've found:
The Pump suction had a ring of silicon sealant on the strainer across to one side of the hole so could possibly have been causing a restriction of flow between the cover plate and the gauze, maybe?
Stripped the pump and the relief valve appears OK. There is scoring on the gear ends and on the casing in way of the driven gear. Appears to be a bit of end float on the drive shaft. Not sure if it's excessive?
The pump did not have a gasket where it bolted to the block, is this normal?
No apparant play in any Big End, Dropped one Big End, The crank is perfect, no scores, nothing. The bearing shells both upper and lower are copper coloured so no white metal left, but no deep scores just appear "well bedded in". the backs have a marking "UO 0.25" that suggests to me the crank has had a regrind.
So what to do?
I don't want to disturb a main in case the upper half shifts (and if it's knackered then it's a new engine anyway) and I dont see the point in dropping another Big End, unless renewing them. I don't have the facilities to change the engine here also I'm on my own ( I replaced the front diff on my own...THAT was difficult enough)
......so I'm thinking, box it up with a new pump, this has 32mm gears, Baxters has 36mm gears (bigger pump, better flow, better pressure...maybe??....shall I get a set of big end bearings and so if where from?..... stick some oil in it, and fingers crossed it was the pump.

If it's the same as it was then.....any one got an AAZ for sale??

I'm a Marine Engineer where the Big End bearings are the width of the truck!...so I'm out of my depth here on these automotive engines.

As allways suggestions/comments very welcome, especially on the state of the bearings and does the pump have a gasket??

Peter

[HarryMann]

The pump did not have a gasket where it bolted to the block, is this normal?
No apparant play in any Big End, Dropped one Big End, The crank is perfect, no scores, nothing. The bearing shells both upper and lower are copper coloured so no white metal left, but no deep scores just appear "well bedded in". the backs have a marking "UO 0.25" that suggests to me the crank has had a regrind.

Sorry to hear this...

No gasket, just make sure the faces are not burred, think bolts 18 ft-lb (presume you have a Bentley manual, some main engine bolt torques are in the Wiki for the AAZ)

Don't like the fact crank has been ground once, rarely a good sign if it's in trouble again

If there's no white metal left then check the others and if the same I'd say that is a pretty bad sign (rarely seen shells right down to the copper all over )

Don't worry about mains but the upper shell can usually be pushed back into place if it slides around a bit, but nor reason why it should if you don't turn the crank.

I wouldn't bother with a new pump TBH Peter... and even a gasket, I'd wrap it now. There's only a very small chance this problem is fixable, and if so, not cheaply.

Like Simon said , chances are then its a fooked motor, you will get some dosh for head (if not seriously cracked) but will need the other bits to put on a replacement. VW short engine about £1200 minimum?

Start asking about for an AAZ... you'll be lucky to get a good JX these days, though I've a set of pistons somewhere.

[Aidan]

you'll be lucky to find a good AAZ, better surely to use a late low mile 1Y with the TD block and turbo it ?

[lloydy]

I got my AAZ by contacting breakers on the web, came up trumps in a couple days, but it is still a gamble, I would now look for a complete car if I could (I just bought a golf with a low mileage 1Z in it, for future use) so you can drive it and get an idea on engine condition.
I think lhd is selling a 1.6na (with extra power?) could be a stopgap til you find a good engine.
There is also a 1.6td multivan for sale on the forum, only £1500 could use the engine and sell the van?
Good luck though, oh yes hate to say it, but a golf gti engine is just as easy as an AAZ to fit and similar mpg