4.5 oil pressure

[irw]

I have been looking at 4.5 Chims, and saw quite nice one last night, Oil pressure was reading just under 30lbs is this ok?, also has some weeping from the power steering pipe joints on the pump, is this a big job?

[mongoose]

you need to be a little more specific as to the revs and oil temp ie was the engine hot or had it just been started etc,also is it a serp engine(i suspect so)?.my 500s(3),one had brand new mains and big-ends fitted during my ownership. all gave identical behaviour on the gauge and as such i find it more difficult than some to subscribe to the gauges are usually inaccurate theory,in other words it would put me off buying a car if i didnt see the same reading again.i get just over the 45 mark on cold start up,then once the oil has warmed through properly the gauge will sit just under this 45 mark at 3000 revs and above.at hot tickover you will get 30 on the gauge and this will drop to 20-25 if left to tickover and get hotter.this is why i use the 3000 revs mark as a more reliable indicator.just remember the gauge takes a little while to react to changes also.all the above running 15-50 oil and on a serp engine btw.

[irw]

Thank you Mongoose,
the reading was taken on tick over, I am going to get it professional inspected - fairly smitten with it.

[petros]

i,m running a 2001 4.5 and oil pressure is just above 25 on tickover when hot, up to 50 at 70mph. as to power steering pipe weep, that seems to be very common, mines got one and it,s took me 3 months to locate a new pipe. weep is very small and isn,t likely to be a problem for a long time. peter

[ntel]

I dont think the gauges are very accurate. My chim, when hot, idles at about 17 psi and at 3000 rpm reads about 35 psi. I know the engine is in very good condition as it had a blue printed rebuild only 4 thousand miles ago. I put 15-40 semi synthetic oil in mine as recommended by the guys at TVR Power.

[mongoose]

ntel said:

I dont think the gauges are very accurate. My chim, when hot, idles at about 17 psi and at 3000 rpm reads about 35 psi. I know the engine is in very good condition as it had a blue printed rebuild only 4 thousand miles ago. I put 15-40 semi synthetic oil in mine as recommended by the guys at TVR Power.

im not into spitefull scaremongering,so please dont take this the wrong way,but if this was my car id get it checked out if that the best pressure you get?.these are similar to the sort of figures i was getting which lead me to discover my mains and big ends were shot,down to the copper,but luckily no crank damage so easy/cheap replacement.it could be down to the sender,the gague,or just the oil grade(ive never used a 15-40 so wouldnt know what to expect here),but this isnt what id expect from a serp engine.also worth remembering that 4000 miles scince a rebuild is certainly no gaurantee that it will be fine now.its worth mentioning that when i rang around dealers quoting my low figures,all thought it was fine/normal.it took a specialist to tell me confidently that it needed further investigation,and i was thankfull i checked it.as soon as the bearings were changed,pressure was restored to 30/45.

[spend]

Does the scale on the gauge matter that much? surely only if it suddenly changes its something to be investigated. If NTel is happy (still getting the special stuff from Hilary?), and TVR Power say its ok then he has simply established his baseline, which I read to be the point of his posting.

An independant pressure check is worthwhile to establish the 'green/red' area for your gauge, if in doubt.

Dave

[mongoose]

spend said:

Does the scale on the gauge matter that much?

only if you want to know the correct oil pressure.

spend said:

surely only if it suddenly changes its something to be investigated.

from the figures im used to,it has changed at some point in the cars life(maybe not in ntels though?).

spend said:

If NTel is happy (still getting the special stuff from Hilary?), and TVR Power say its ok then he has simply established his baseline, which I read to be the point of his posting.

have tvr power said its ok?they are one of the dealers that got it wrong with my diagnosis anyway(theres common confusion with v8 oil pressures),so would they be right?.interesting that they use 15-40 oil also,when the top specialists prefer 15-50. i agree about establishing a baseline,but the lower your gauge reads,then the less margin for error you have to spot if and when things start to go wrong.

spend said:

An independant pressure check is worthwhile to establish the 'green/red' area for your gauge, if in doubt.

agree strongly.well worth knowing if your gauge is out.the whole point of my post really.its not worth being complacent about oil pressure,and its good to know your gauge works correctly and is accurate,which is its real value of course,otherwise we'd just have a low pressure light.having lost my bottom end bearings,i wouldnt want someone else to go through the same,all for the sake of a simple check or two.

[ntel]

Just to clear a couple of things up.

My engine was rebuilt at 50,000 miles mainly because of excessive oil consumption. The oil pressure gauge did read lower before the rebuild although I cant realy recall the figures. The oil pressure readings are always consistant and, as Spend mentioned, I use this as a baseline.

Since the rebuild, oil consumption is next to nothing and the engine runs sweet as a nut. All bearings were changed as well as the cam (which was only showing slight wear).

BTW Spend, the special stuff from Hillary Briss is better than ever.