Technical Tipo TD - oil pressure query

[jonti]

I've fitted a new oil pressure sensor and the gauge has come back to life recording a steady 1.3 bar (where 3 is the middle and 6 is the max). A long time ago I'm sure it was around 2.5, increasing on acceleration. What readings do other TD owners get and 2) are there adverse consequences from a pump that may be tired (but with cam cover off can still spray oil 2 feet away from the engine !?)

Cheers

 

[Tipo Jack]

I seem to remember (without going out to the car to check) that the gauge reads zero to six and three is central right? Mine is always about a third of the way beyond the 3 from cold startup and then a similar distance below it when warm and ticking over. As the revs rise when warm it gets to about 3. I think this is normal.

If yours is only getting 1.3 bar from cold I think it must be too low. The pressure should be higher when cold as the oil is thicker. Could just be the wrong type of sender perhaps? I think if it was genuinely that low it would come on gradually rather than give you a sudden change.

 

[jonti]

Cheers for this jack. I think my gauge did similar to yours at one time. I think the oil pump has probably had it (the cars done alot of miles) and its going to have to be changed.

 

[Tipo Jack]

Why not try some thick oil additive like "stop smoke"? It might thicken the oil enough to up the pressure a bit perhaps?

 

[jonti]

I'm using semi synthetic as advised by Sumplug which I am presuming is thinner than the pure mineral stuff? However, I did have the pressure tested by an engine person a while back and the technical diagnosis was 'not brilliant' so I'll have to stop stalling and roll my sleeves up.

 

[Tipo Jack]

As the engine wears, the gaps between bearings and crankshaft, pistons and cylinders, within the oil pump etc. all get bigger and so a thinner oil is not a good idea. Just because your oil is semi sythetic it does not mean it'll be thinner either. Check the weighting - I use 20W40 diesel turbo stuff from Wilcos. If yours is thin then just changing back to the thicker stuff may well solve your problem.

This is why older classics often use 20W50 but modern engines like a zetec with close tolerances use 0Wwhatever!

 

[sumplug]

Nope, the semi syn oil 15w/40HD will not be too thin. What happens with all oils, is when the oil gets very hot, it goes thinner. if the engine tends to run hot, oil will heat up more then usual and so your oil pressure will decrease slightly. Its not oil related, but coolant related and needs attention. Semi syn also will stay in viscosity longer then mineral oil, so will not need changing so often. I always change oil no lomger then 3000 miles petrol or diesel.
Mileage is not an indication of wear. Service maintenance determines the longevity of an engine. Lack of it can have an engine worn out within 50000 miles, or good maintenance can have a healthy engine at 150000 miles.
If the engine you think is worn, then go to 15w/50 semi syn HD/SL spec.

Andy.

 

[jonti]

I'm happy with semi synth. The engine runs pretty cold - this is clear from the fan heater and the sensor + gauge reaffirm this (they shot up when I forgot to put coolant in once !) Compression is also good, despite the miles, it starts very well from cold since the new head was changed with a different glowpugs + control unit.

I'm going to try and swap the pump over :yuck: this Spring and see what happens.

 

[jonti]

Lovely clean oil pump removed from the spare engine !

How does an oil pump wear out given that its just a wheel going round (in lots of oil too!) Is there a relief valve that can go - or is it gaskets? The pump on the car is covered in oily gunge.......which has built up again since cleaning when fitting the head. In reality, I presume the chances of the oil pick up getting clogged must also be pretty low??

 

[sumplug]

View attachment 25258

Lovely clean oil pump removed from the spare engine !

How does an oil pump wear out given that its just a wheel going round (in lots of oil too!) Is there a relief valve that can go - or is it gaskets? The pump on the car is covered in oily gunge.......which has built up again since cleaning when fitting the head. In reality, I presume the chances of the oil pick up getting clogged must also be pretty low??

This type of oil pump is a lot more reliable then previous types. Problems are usually with the return valve sticking. Wear can occur like a wheel bearing on pump wheel so check for excess play here. Pickup is usually fine if oil changed regular but what can damage the pump and engine is if the sump is dented upwards towards the pickup and all the silt/crud laying on the sump floor gets sucked up. Indeed, this is how the daft design of the 12v 1.4 engine got worn out so quickly. the design let the pickup to close to the sump floor. By shortening the pickup, this eradicated the problem.
Going back to the Tipo TD. Oil pressure is usually fine. Its the guage and the sender unit that play up. A misreading guage was/is common. A way to test your compression as well, is to put your hand over the camcover oil cap hole and feel the suction. If its quite strong, all is well.
Remember, its not the oil pump thats reducing the oil pressure, but a worn engine. Rings and bearings that are worn will reduce the pressure down. you could have a pressure test done to find out.

Andy.