Hydraulic followers, and wrong grade of oil.

L

Lofty

Guest

• Sep 10, 2004

• #1

Your advice please gents, could hydraulic followers "pump up" if too
heavy a grade of oil was used?

I have had difficulty starting when hot on my 3.9 Disco, ( symptoms
appear to be low compression and flooding) , testbook reveals no
problems with the fuel system, ignition has good spark when the fault
occurs, only way to start engine is to pull the fuel pump fuse, crank
as per flooded engine on full throttle, and then bung the fuse back in
when it catches.

Trouble is, it won't always repeat the fault, but GF noticed last time
it happened, engine seemed to be turning over as if plugs were
removed.

Its only happened since the last service, (and the hotter weather) and
I believe 20w50 was put in.

Your collective advice keenly sought.

Lofty

 

B

Badger

Guest

• Sep 10, 2004

• #2

"Lofty" <[email protected]> wrote in message
news[email protected]...
> Your advice please gents, could hydraulic followers "pump up" if too
> heavy a grade of oil was used?
>
> I have had difficulty starting when hot on my 3.9 Disco, ( symptoms
> appear to be low compression and flooding) , testbook reveals no
> problems with the fuel system, ignition has good spark when the fault
> occurs, only way to start engine is to pull the fuel pump fuse, crank
> as per flooded engine on full throttle, and then bung the fuse back in
> when it catches.
>
> Trouble is, it won't always repeat the fault, but GF noticed last time
> it happened, engine seemed to be turning over as if plugs were
> removed.
>
> Its only happened since the last service, (and the hotter weather) and
> I believe 20w50 was put in.
>
> Your collective advice keenly sought.
>
> Lofty

If it's a pre-serpentine engine, then 20W50 is the correct grade of oil. If
it is a serpentine-belted engine (whether it has a dizzy or coil packs) then
it'll run 10W40 or 15W40 due to the different oil pump arrangement.
(Serpentine and a dizzy = rare front timing cover with late-style pump.)
BUT - oil grade won't be the cause, the hydraulic lifters are the same part
number regardless, right from the P6 rover up to the latest 4.6. Sounds as
though you have a hot enrichment fault, I'd start by looking at the ecu's
water temp sender. Oh, and do a compression test, you might have glazed
bores.

--
Badger.
B.H.Engineering,
Rover V8 engine specialists.

now live but still under construction,
www.bhengineering.co.uk
www.roverv8engines.com
www.roverv8engines.co.uk
No replys now for 3 weeks, away on business.

 

E

EMB

Guest

• Sep 10, 2004

• #3

Lofty wrote:

> Your advice please gents, could hydraulic followers "pump up" if too
> heavy a grade of oil was used?


Nope - I use 20W/50 in several customers 3.5's with no problem - I's be
looking for the cause of the flooding, maybe leaky injectors filling the
cylinders whilst stopped?
--
EMB
change two to number to reply
---------------

Old age is the outpatients department for purgatory.

-John Morton

 

L

Lofty

Guest

• Sep 10, 2004

• #4

On Sat, 11 Sep 2004 09:44:02 +1200, EMB <[email protected]> wrote:

>Lofty wrote:
>
>> Your advice please gents, could hydraulic followers "pump up" if too
>> heavy a grade of oil was used?
>
>
>Nope - I use 20W/50 in several customers 3.5's with no problem - I's be
>looking for the cause of the flooding, maybe leaky injectors filling the
>cylinders whilst stopped?

Thanks chaps,

It is a serpentine belt system, so far its had both temperature
thermistors changed, new throttle pot, tested stepper motor ( no
fault) tested Lambdas ( no fault ), tested mass air meter (no
fault), new coil ( just in case, but loads of spark anyway).

Have thought about leaky injectors, but the fault is more likely to
emerge after the car has been stuck in traffic and hotter than usual (
can hear fan drive cut in) then leave car for 15 - 20 minutes, but if
you do the same thing again it starts ok.

Is it possible to test the fuel rail pressure for leaking injectors
while the engine is stopped?

I can see the test point, but am not sure if pressure leaks back to
tank when pump is off.

would leaky injectors cause any other faults, emissions are normally
good, well within tolerance, any other start apart from a very hot one
is fine.

Lofty

 

T

terry

Guest

• Sep 11, 2004

• #5

Lofty wrote:
> Your advice please gents, could hydraulic followers "pump up" if too
> heavy a grade of oil was used?
>
> I have had difficulty starting when hot on my 3.9 Disco, ( symptoms
> appear to be low compression and flooding) , testbook reveals no
> problems with the fuel system, ignition has good spark when the fault
> occurs, only way to start engine is to pull the fuel pump fuse, crank
> as per flooded engine on full throttle, and then bung the fuse back in
> when it catches.
>
> Trouble is, it won't always repeat the fault, but GF noticed last time
> it happened, engine seemed to be turning over as if plugs were
> removed.
>
> Its only happened since the last service, (and the hotter weather) and
> I believe 20w50 was put in.
>
> Your collective advice keenly sought.
>
> Lofty

If a petrol floods badly enough, the fuel will wash all traces of oil
from the bores and rings, which will give symptoms as of low
compression, especially on worn/higher mileage engines. This is a
general observation of all petrol engines, not specifically disco's.

Terry

 

L

Lofty

Guest

• Sep 11, 2004

• #6

On Sat, 11 Sep 2004 10:11:18 GMT, terry <[email protected]>
wrote:


>
>If a petrol floods badly enough, the fuel will wash all traces of oil
>from the bores and rings, which will give symptoms as of low
>compression, especially on worn/higher mileage engines. This is a
>general observation of all petrol engines, not specifically disco's.
>
>Terry

Thanks Terry,

A very good point, this engine has only done 37K and normally used for
reasonably long trips.

I have narrowed the flooding down to the righthand bank ( drivers
side), and its so bad when the fault occurs that petrol is seen
weeping around the exhaust manifold to downpipe joint.

If the engine starts, it will only be running on the lefthand bank,
the righthand exhaust manifold will be cold enough to touch.

I put the " cold side" down to the ECU shutting off that bank of
injectors due to the Lambda sensor detecting an overfuel situation,
but I am only guessing.

That was the only fault detected by the testbook, but it didn't say
why it did it.

I hate intermittent faults.

Leaking injectors are still favorite, but would they only give a
problem after being heat soaked?

All suggestions very welcome

Lofty

 

A

Austin Shackles

Guest

• Sep 11, 2004

• #7

On or around Sat, 11 Sep 2004 09:44:02 +1200, EMB <[email protected]>
enlightened us thusly:

>Nope - I use 20W/50 in several customers 3.5's with no problem - I's be
>looking for the cause of the flooding, maybe leaky injectors filling the
>cylinders whilst stopped?

20W/50 was standard for a long time. Mind, I use "Castrol GTX for high
mileage engines" in my current 3.5i.

 

E

EMB

Guest

• Sep 11, 2004

• #8

Austin Shackles wrote:
> On or around Sat, 11 Sep 2004 09:44:02 +1200, EMB <[email protected]>
> enlightened us thusly:
>
>
>>Nope - I use 20W/50 in several customers 3.5's with no problem - I's be
>>looking for the cause of the flooding, maybe leaky injectors filling the
>>cylinders whilst stopped?
>
>
> 20W/50 was standard for a long time. Mind, I use "Castrol GTX for high
> mileage engines" in my current 3.5i.
>

GTX is what I actually use - it's still a 20W/50 here.

--
EMB
change two to number to reply
---------------

Old age is the outpatients department for purgatory.

-John Morton

 

A

Austin Shackles

Guest

• Sep 12, 2004

• #9

On or around Sun, 12 Sep 2004 09:37:16 +1200, EMB <[email protected]>
enlightened us thusly:

>Austin Shackles wrote:
>> On or around Sat, 11 Sep 2004 09:44:02 +1200, EMB <[email protected]>
>> enlightened us thusly:
>>
>>
>>>Nope - I use 20W/50 in several customers 3.5's with no problem - I's be
>>>looking for the cause of the flooding, maybe leaky injectors filling the
>>>cylinders whilst stopped?
>>
>>
>> 20W/50 was standard for a long time. Mind, I use "Castrol GTX for high
>> mileage engines" in my current 3.5i.
>>
>
>GTX is what I actually use - it's still a 20W/50 here.

bah. 15W40 or summat here. it's increasingly difficult to get
averagely-decent 20W50 in this country - plenty of utter ****e around and
such as silkolene still make it for classic racers and the like, at ruinous
expense. I did have some of the latter for the bike, mind.

 

E

EMB

Guest

• Sep 12, 2004

• #10

Austin Shackles wrote:

> bah. 15W40 or summat here. it's increasingly difficult to get
> averagely-decent 20W50 in this country - plenty of utter ****e around and
> such as silkolene still make it for classic racers and the like, at ruinous
> expense. I did have some of the latter for the bike, mind.

How much quality 20W/50 do you want? I'll ship it to you if you want to
pay. Quality stuff retails here for somewhere between 8 and 10 quid for
4 litres.

--
EMB
change two to number to reply
---------------

Old age is the outpatients department for purgatory.

-John Morton

 

A

Austin Shackles

Guest

• Sep 12, 2004

• #11

On or around Mon, 13 Sep 2004 07:23:40 +1200, EMB <[email protected]>
enlightened us thusly:

>Austin Shackles wrote:
>
>> bah. 15W40 or summat here. it's increasingly difficult to get
>> averagely-decent 20W50 in this country - plenty of utter ****e around and
>> such as silkolene still make it for classic racers and the like, at ruinous
>> expense. I did have some of the latter for the bike, mind.
>
>How much quality 20W/50 do you want? I'll ship it to you if you want to
>pay. Quality stuff retails here for somewhere between 8 and 10 quid for
>4 litres.

not using it any more, I've not got any old V8s with oil leaks.