Oil Pressure Weird Readings

[russellbaldwin]

Hi,

 

I have a 125bhp TR6 with TRGB rebuilt engine about 3000 miles ago converted to unleaded and with a spin-on oil filter conversion. I had a small oil leak which I couldn't trace and may have been due to over-filling slightly with oil. I've changed the oil and filter and it's using Magnatec oil.

 

I've started to get some weird readings through the oil pressure guage. On startup the engine registers 70 psi and will settle to around 50-55psi on idle and sometimes less when engine warm. When accelerating the pressure sometime DECREASES sometimes down to zero and the needle will float backwards and forwards. Has anyone seen something like this before - I don't know whether it's the guage or something more serious like a blockage or a problem with the pump.

 

Any help appreciated!

 

thanks

Russell.

[Dave JRH]

Hi Russell,

 

Sounds like your problem is being caused by oil surge. This is happening due to acceleration and braking and is usually prevented by baffles installed in the sump.

 

Never having removed the sump (yet) i cannot vouch for their existance.

 

Someone more versed in such items will no doubt add more substance, or shoot my theory down.

 

Regards

 

Dave

[Tom Fremont]

Some oil cooler thermostats will cause the pressure to dither, but it's not related to accelerating, just the cycling of the cooler circuit ( normally closed ) which upon opening will see a momentary drop ~ 15-20 psi then a jump up to + ~10 psi before steadying in the closed mode. Mine cycles about every 15 seconds when cruising at 70 mph.

[jerrytr5]

There are no baffles in a standard TR sump, and unless it's virtually empty (of oil) a TR doesn't pull enough G to cause oil surge under acceleration. Braking and cornering maybe.

I'd try a different guage and pipe first.

Incidentally, does the oil light illuminate when the guage goes down to zero under these conditions?

Jerry

[Don York]

Hi,

 

I have a 125bhp TR6 with TRGB rebuilt engine about 3000 miles ago converted to unleaded and with a spin-on oil filter conversion. I had a small oil leak which I couldn't trace and may have been due to over-filling slightly with oil. I've changed the oil and filter and it's using Magnatec oil.

 

I've started to get some weird readings through the oil pressure guage. On startup the engine registers 70 psi and will settle to around 50-55psi on idle and sometimes less when engine warm. When accelerating the pressure sometime DECREASES sometimes down to zero and the needle will float backwards and forwards. Has anyone seen something like this before - I don't know whether it's the guage or something more serious like a blockage or a problem with the pump.

 

Any help appreciated!

 

thanks

Russell.

 

 

Can't help with the oil pressure problem as my rebult enging has the reverse issue of high presure, but it is starting to decrease slightly with 5000 miles on the clock. I would comment on the oil leak as I have tried to cure mine for weeks. It was coming from the spin on adaptor to the engine block. The answer came from Martin at TR Revington, he suggested using a sealing compound called Heldite. After dipping the "O" ring in the tin before refitting into the block it sealed the leak.

[EricTR6]

I'd try a different guage and pipe first.

 

Jerry

 

I agree with Jerry. Maybe your gauge oil line is leaking. Air in the oil line can cause strang readings.

[russellbaldwin]

Thanks for the advise. A friend has a vitesse that has the oil pressure pipe and light feed at the same point on the engine block. I only have an electrical connection in the same place for the oil light. Any ideas where I can find the pipe on the blovk so I can trace from there?

 

I'll change the oil and filter gain and try the sealant (and check the oil pipe feed to the guage. If none of that works, I'll try the guage and go from there.

 

Thanks again,

Russell.

[EricTR6]

See this picture and look at number 23 ; http://www.rimmerbros.co.uk/tr6/images/8a.gif

 

Cheers,

 

Eric