d181s
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Post by d181s on Jun 18, 2019 8:19:08 GMT
Hi folks,
Wondering if anyone has input...
Previously :- 30k Miles, normal oil pressure ( which only dips at warm idle) & the green oil light was always on since I bought the car.
Upgraded :- Camshafts, tappets and High Volume Oil Pump
Now :- Normal Oil pressure at cold start, then drops to border of Red-Green when warmed up. At revs, does climb a little. At longer idles, on a hot engine, drops into Red zone.
Temperature a consistently at middle (normal) and use the 78c termostat plus electric fan with its on thermostat.
Engine oil : Semi Synthetic 10w-40 both before and after.
Next steps:- 1) Change the Oil Pressure switch and Oil Sender
Appreciate any input if this would address the problem?
Thank you
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Post by enigmas on Jun 18, 2019 9:24:38 GMT
The oil you're using is not suitable for a Rover V8 of that vintage. Use something like Penrite 20/60 with ZDDP (dyno oil)...definitely not a modern 10/40 synthetic oil. A synthetic oil is too thin for these GM designed engines...this includes the bearing tolerances. The oil pumps were designed for high volume oil delivery not high pressure. Here's a link...it would be worth your while reading the literature especially with regard to ZDDP. www.penriteoil.com.au/products/classic-light-20w-60-mineral#/
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d181s
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Post by d181s on Jun 18, 2019 10:20:16 GMT
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Post by enigmas on Jun 18, 2019 10:28:19 GMT
The 20/50 should be fine. What is the condition/age of the engine.
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d181s
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Post by d181s on Jun 18, 2019 10:38:42 GMT
Mileage was 29xxx miles when I got her. Now sits at 31xxx miles.
Just had the head gaskets changed when did the cam work.
Overall she was a sweet runner, everything stock standard.
So hoping to “fix” this oil pressure issue - and praying it wasn’t caused by the upgrade.
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Post by johnwp5bcoupe on Jun 18, 2019 11:40:22 GMT
The oil you're using is not suitable for a Rover V8 of that vintage. Use something like Penrite 20/60 with ZDDP (dyno oil)...definitely not a modern 10/40 synthetic oil. A synthetic oil is too thin for these GM designed engines...this includes the bearing tolerances. The oil pumps were designed for high volume oil delivery not high pressure. Here's a link...it would be worth your while reading the literature especially with regard to ZDDP. I wont now use anything else but Penrite Vince
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d181s
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Post by d181s on Jun 19, 2019 11:30:47 GMT
Gents...
An interesting conundrum (atleast to me)... so I seek your input:-
There’s only One (1) 5 Liter can of the Classic Mini (20w50) and Classic Medium (20w70) available at this time.
So my options would be:-
(A) Use all the 20w50, and top off with the 20w70 (B) Use all the 20w70, and top off with the 20w50 (C) Do some blending - maybe 50-50 of each ( hope of getting closer to 20w60 - which is the Classic Light)
Or some other combination.
Your thoughts are much appreciated.
Ps: I have placed an order for a case (4x 5Liters of Classic Light) which should be in sometime August! 😩
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Post by enigmas on Jun 19, 2019 12:36:15 GMT
You may be over thinking this oil change. Unless the car's bearing clearances are really loose or the oil pump end plate has not been fitted to ensure minimal endplay for the pump gears use the 20/50 and top up with the 20/70.
As an aside, despite what most experts recommend I like to warm the engine in my coupe (gentle fast idling...absolutely no revving) before driving off each morning. This ensures the oil has reached all the critical components and the engine has warmed sufficiently. Same engine fully rebuilt built over 25 years ago with over 300,000km.
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Post by lagain on Jun 19, 2019 19:23:10 GMT
I know that every one has their preference for engine oil, but the proof of the pudding is in the eating - or engine wear and that is very difficult to evaluate.When I was in the Stag club they had organised a discount with a motor accessory shop, whose name escapes me, for a Valvoline 20/50 that was a classic racing oil with a high ZDDP content, I used it a few times, but now use Millers classic sport semi synthetic, which seems OK but gets thinner when hot.
What I would never ever use in a rebuilt engine is what was recommended when our cars were new, such as Duckhams Q. My mower used exactly the same oil and the engine wore out !
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d181s
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Post by d181s on Jun 20, 2019 3:37:12 GMT
Gents...
So here’s an update...
At the workshop right now, and decided to just drain the oil from the sump plug. Since only 5liters came out, decided to replace it with 20/70 (Classic Medium). The thinking here is the remaining approx 2liters of 10/40 should thin it out a bit.
Immediately noticed smoother engine and better oil pressure but still worse than before I changed to the High Volume Pump.
Then in occurred to me... I ordered the Heavy Duty Relief Spring too. Was it changed?
Quick check with the foreman and realized it wasn’t changed and it missing now.
I read somewhere on the boards of using a small spacer to strengthen the spring. So that’s the next step for now... br] The foreman is proposing “pulling” out the spring instead (extending it by 10mm) - which seems to have improved oil pressure for now.
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Post by djm16 on Jun 20, 2019 4:59:59 GMT
That treatment of the spring will not last. Order the correct one ASAP!
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d181s
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Post by d181s on Jun 20, 2019 5:59:22 GMT
Just placed my order for:-
- Heavy Duty Relief Spring - Relief Valve - Oil Pressure Switch - Oil Pressure Sender
Hopefully this will eliminate failure points and give me some confidence with this part of the system.
The questions that remain:-
1) Previous operating temperature for the car would be anywhere between “Just past Cold” to the “Mid-way of Normal” with glycol based coolant. Having installed the 82c thermostat the reading now heads from slightly more than “Mid-way of Normal” to about a “quarter to Red”. Should I remove the thermostat?
I’m in Malaysia where the weather typically ranges from 32c all the way to 40c throughout the year. Maybe the radiator ( recently flushed) and with A/C is struggling to sufficiently cool the engine?
2) Could the “excess” heat buildup be causing the lower oil pressure? Again, not something I experienced before.
3) Could there be something with the “high volume oil pump”? Would reverting to the original pump help?
Thoughts on the process of elimination most welcome.
Thank you
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Post by enigmas on Jun 20, 2019 13:03:55 GMT
The standard oil pump should be fine...and if you've uprated the pump gears (slightly longer with an adaptor plate) that should be fine too. You really don't want to up the pressure beyond the factory specs as it loads up the skew gears that drive the pump...causing other issues. The correct heavier viscosity oil should improve the low oil pressure issues you're having.
You didn't state earlier that you were in Malaysia with the ambient temperatures being much higher than what is likely in the UK.
You also didn't state that the car runs an aircon system.
Both these factors effect engine cooling or the requirement to dissipate heat.
Sources of Heat. 1. Transmission cooling. Consider fitting an add-on 'air-cooled' transmission cooler to the car in 'series' with the trans cooler circuit currently passing through the bottom radiator tank in a heat exchange fashion. Add it to the exiting line returning to the transmission.
2. Aircon Condensor. Fit an electric fan to the aircon condensor that switches on whenever the aircon is being used...especially in static traffic.
3. More efficient Mechanical fan. Consider fitting a high efficiency flex fan in place of the factory mechanical fan or fitting a large electric puller thermo fan behind the radiator.
4. Larger 3 core alloy radiator. The original factory standard P5B radiator is only 2 core AFAIK. It will prove marginal in dealing with the temperatures you state, especially when running an aircon.
5. Alternator. If you add a couple of electric fans you may also need to upgrade the alternator due to the increased electrical load.
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Post by johnwp5bcoupe on Jun 20, 2019 13:58:32 GMT
I don't think anyone in the UK would be able to advise you 100% on what you need to survive under those conditions best listen to the guys over the pond like Vince who do get extreme extended temperatures!!
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d181s
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Post by d181s on Jun 20, 2019 14:33:46 GMT
The standard oil pump should be fine...and if you've uprated the pump gears (slightly longer with an adaptor plate) that should be fine too. You really don't want to up the pressure beyond the factory specs as it loads up the skew gears that drive the pump...causing other issues. The correct heavier viscosity oil should improve the low oil pressure issues you're having. You didn't state earlier that you were in Malaysia with the ambient temperatures being much higher than what is likely in the UK. You also didn't state that the car runs an aircon system. Both these factors effect engine cooling or the requirement to dissipate heat. Sources of Heat. 1. Transmission cooling. Consider fitting an add-on 'air-cooled' transmission cooler to the car in 'series' with the trans cooler circuit currently passing through the bottom radiator tank in a heat exchange fashion. Add it to the exiting line returning to the transmission. 2. Aircon Condensor. Fit an electric fan to the aircon condensor that switches on whenever the aircon is being used...especially in static traffic. 3. More efficient Mechanical fan. Consider fitting a high efficiency flex fan in place of the factory mechanical fan or fitting a large electric puller thermo fan behind the radiator. 4. Larger 3 core alloy radiator. The original factory standard P5B radiator is only 2 core AFAIK. It will prove marginal in dealing with the temperatures you state, especially when running an aircon. 5. Alternator. If you add a couple of electric fans you may also need to upgrade the alternator due to the increased electrical load. Thank you for the detailed post - very much appreciated! Let me go thru this checklist:- 1) Transmission oil cooler - have explored this / and even an engine oil cooler, without any proper space for placement. Ideas would be most welcome. 2) Aircon Condensor Fan - have 2 units placed behind the grill and before the radiator. These are also thermostat controlled to come on even if the A/C isn’t on, especially in heavy traffic conditions. 3) Viscous fan - explored this, however lack clearance between the waterpump /fan spindle and the radiator. Considered machining / cutting the spindle off to fit an electric fan, but again none slim enough here in Malaysia. What’s a “high efficiency flex fan”? And where can I get one? 4) Radiator is original and will consider a 3 core if all else fails. Gents, the only thing different is that I’ve put in a new 82c Thermostat. Could the old one have been jammed open, and therefore, masking the heat load. Prior to this, I’ve not experienced any heat issues whatsoever.
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Post by Brendan69 on Jun 20, 2019 15:01:52 GMT
It usually says in most cars user handbooks about different grades of oil for differing climates which should go some way to assist you with your decision.
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Post by johnwp5bcoupe on Jun 20, 2019 15:18:13 GMT
I fitted the Mk3 transmission cooler one of the best things I have done! if you can find one all the mountings are in place, you have to do a bit of configuring with the pipework! it doesn't need high pressure fittings. the Mk3 cooler gets the benefit of a large area presented to the radiator. Rover obviously saved a few £/s/d incorporating the cooler in the radiator Or you can just fit an aftermarket cooler.
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Post by enigmas on Jun 20, 2019 23:05:46 GMT
FYI. I live in OZ Victoria and do get extreme temperatures in summer...up to 40c. The pix below are of my Rover P5 MK3 coupe (hybrid) Leyland P76 4.4 litre V8 fitted. 4 core alloy radiator. Flex fan Radiator shroud fabricated around the flex fan. Twin thermo fans in front of aircon condensor. (The condensor sits lower than the radiator) Air cooled mk3 trans cooler sits below the radiator. (Not in the original factory position) Engine temp runs at 180°F consistently. Lower bypass thermostat housing fabricated (160°F) and works in conjuction with a top 180°F thermostat. Lower thermostat unit. NB. Two Flex fans in my stash. The one on the RHS is a 1970s Factory Ford V8 aircon fan. The 4 bolt pattern (both fans) suit the Rover waterpump drive flange pattern. PM me if you want one but can't obtain one. Flex fans pull a lot of air at low engine speeds (idling). As RPMs increase the flexible blades straighten out pulling less air. They are very efficient especially if fitted with a shroud. Another benefit of large mechanical fans in hot climates is that they produce a constant stream of air over the engine and ancilliaries when idling in traffic.
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d181s
Rover Rookie
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Post by d181s on Jul 2, 2019 4:34:11 GMT
Hey everyone,
Sorry for the delayed reply... with work and stuff, it’s been awhile to get around to solving this.
So here’s what’s been done so far:-
1) The new Heavy Duty Relief spring was fitted along with new Valve, switch and sensor. Readings seem accurate and the “always on green light” now switches off and there’s great oil pressure now.
2) The car did come with the 13 blade fan and a 3 core radiator. We noticed the radiator has had some botched welds that may have caused issues. So it’s been replaced with a new, better flowing, 3 core radiator.
3) The 82c thermostat is in place and when up to speed, keeps the engine at 98.9c. So that’s working a peach!
So what’s the problem then?
Everything seems great... until a bit of traffic, the stop-start doesn’t help cooling and the temp rises ever so slightly.
From that point, oil pressure starts to drop significantly. For example it would be at midway (N) before the slight temp rise. Then will start dropping, and the longer I’m stuck in traffic, goes all the way down to the red-zone (L). I haven’t risked the light coming on yet, and just pull over to cool things down.
Here’s the question then.... could the entire cooling system be operating right at its limit, that the increase load from stop-start traffic, heats the transmission just a little more, that the radiator isn’t able to sufficiently cool the engine from that point on?
There are 2 proposed solutions from this point:-
A) Find a suitable spot, maybe infender and plumb a Trans cooler. B) Plumb a water cooled oil-cooler - the compact kind found on modern Honda’s
Any thoughts?
Thank you again for the support
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Post by enigmas on Jul 2, 2019 7:18:07 GMT
Note that if there's no heat exchange occurring under the car's bonnet things just get hotter and hotter! For cooling to occur effectively hot air must also exit the engine compartment. The P5 has a bonnet that contains heat very effectively within the engine bay. If the car is moving forward the air stream forced thrpugh the radiator is sufficient to evacuate the hot air under the car...the only place it can exit. Cars of the 20s and 30s had vented/louvred bonnets and cowls for good reason. To enable a through flow of air. Hot air rises...it doesn't drop down...hence hot air balloons. Modern cars vent the engine compartment to the rear of the bonnet at the base of the windscreen.
Humour me and try the following. Remove the bonnet and go for a slow drive...it doesn't have to be in congested traffic just dawdle along in quiet backstreets. Stop and allow the car to idle for a considerable time as though it were in congested traffic.
I think you'll find that the engine will maintain a more steady even temperature if both your mechanical and electric fans are properly setup.
* If you are happy with the result the rear sections of the bonnet can have vents or louvres incorporated...as a friend of mine did with his P5.
NB. Another common source of overheating/hot running at low speeds is incorrect ignition timing. If the initial (static) timing is too retarded (discount where the WSM says its supposed to be) try advancing it. If the initial timing is too late (retarded) it heats the engine block. Move it up to around 10° BTDC at idle....and see how it runs for extended periods stationary!
If the engine then pings at faster engine rpm under load but doesn't overheat with prolonged stationary periods have the distributor recalibrated/remapped to reduce the rate of advance at higher rpm.
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d181s
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Post by d181s on Jul 2, 2019 10:40:18 GMT
Hi Vince,
The Timing is at 10 degrees BTDC and has been thru this entire exercise - it’s been set and rechecked since it was brought up here.
If you will remember, all this started after the 82c Thermostat was installed, and without the thermostat, the engine doesn’t reach “N” on the gauge.
So the thought occurred, maybe the thermostat doesn’t open enough to allow sufficient coolant circulation. We’ve made a small hole on the older thermostat and will test this theory tomorrow.
The logic here being, if that works, then I will be sourcing a high-flow 82c Thermostat the likes of Tridon (AU) as a replacement.
I do like the idea of venting the hood / bonnet. And my predicament is my car is an original paint 30,xxx mile car! So there in lies the dilemma.
Cheers!
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Post by enigmas on Jul 2, 2019 15:41:25 GMT
If the car is pristine then why not try and source a second hand bonnet. I believe any model P5 bonnet will fit...and have that one modified.
Have you tried idling it (stationary) for lengthy periods with the bonnet open to gauge the result?
Running the cooling system without a thermostat is not really efficient as coolant needs to have 'residence' time in the radiator for effective heat exchange to occur...otherwise coolant simply rushes through without being cooled. Engine temperature can then be very erratic.
Trapped air pockets at the rear of the block (high up) will also cause over heating issues. If gurgling sounds can be heard at the top radiator hose on a hot engine then this is the issue.
The only other causes for overheating (given that the car is so low mileage) is a silted block internally.
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d181s
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Post by d181s on Jul 3, 2019 14:09:48 GMT
What a relief... it’s sorted!
It seems the 82c Thermostat is restricting coolant flow, and therefore when in start/stop traffic and the load from the Gearbox and AC, just can’t cope with sufficiently cooling down.
We drilled a few holes on the flange of the old thermo and although it takes a little longer to get up to temp, is working a great in traffic conditions!
So the next step is the source a high-flow thermostat from Tridon Australia, unless anyone has alternate or “better” thermo options?
Cheers!
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Post by djm16 on Jul 4, 2019 7:09:21 GMT
Way back in this thread, you said that you were using a glycol based coolant.
If your outside temperature never gets below 0C, I recommend using a corrosion inhibitor only (plus water) coolant. Glycol has a significantly lower specific heat capacity than water, which means that for the same rate of heat transfer, the coolant has to get hotter.
In Perth WA, I change my coolant twice per year: water / inhibitor only in Summer (20 to 40 C) and glycol 50% in Winter (-3 to 25 C).
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Post by enigmas on Jul 4, 2019 15:22:42 GMT
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