Disco 1 3.9 V8 - Cranking speed?

Disco 1 3.9 V8 - Cranking speed?

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Discussion

marksx

Original Poster:

5,052 posts

189 months

Sunday 9th February 2014
quotequote all
How fast does the starter normally turn these things over when all is well?

I've just picked up my first ever Disco, and to me it seems too slow when turning over, as if the battery is flat sort of speed. (It isn't, it's the same with boosters on).

When I picked it up, it fired. Went to fill it up a couple of miles later and it wouldn't go. Now it starts Ok but still cranks slowly.

Any thoughts?

Thanks

camel_landy

4,863 posts

182 months

Sunday 9th February 2014
quotequote all
Cranking speed is more important for diesels...

...however, a dead battery or poor electrics aren't going to help a petrol.

M

HarryW

15,150 posts

268 months

Sunday 9th February 2014
quotequote all
RV8's in my experience from TVR's either fire quickly or mess around, killing a battery toot sweet, between cranks always switch the ignition fully off to allow the stepper motor to reset before cranking again.
Chances are you just have a tired old battery fitted.

paintman

7,669 posts

189 months

Sunday 9th February 2014
quotequote all
Or the engine to body earth leads are badly corroded. Common as vehicles age. The plastic covered ones can corrode away under the sheath so whilst the ends look OK there's little or nothing there.
Try connecting a jump lead from the battery earth terminal directly to the block & see if that improves matters.
Wouldn't hurt to fully charge the battery with a mains charger just to check.

marksx

Original Poster:

5,052 posts

189 months

Monday 10th February 2014
quotequote all
paintman said:
Or the engine to body earth leads are badly corroded. Common as vehicles age. The plastic covered ones can corrode away under the sheath so whilst the ends look OK there's little or nothing there.
Try connecting a jump lead from the battery earth terminal directly to the block & see if that improves matters.
Wouldn't hurt to fully charge the battery with a mains charger just to check.
I'll try that when I get home, thanks.

Then I'll look at another battery.

marksx

Original Poster:

5,052 posts

189 months

Tuesday 11th February 2014
quotequote all
Well, direct earth connection from battery to lifting eye didn't improve anything.

On an unrelated note. A rattle from the V8 as it gets warm can only be a good thing, right?

hehe

paintman

7,669 posts

189 months

Tuesday 11th February 2014
quotequote all
Depends entirely what the rattle is.
Not if its the tappets. These are hydraulic & whilst its not unusual for them to drain down if parked up for a period of time the initial rattle should quickly disappear as they fill.
Depending on the year of your vehicle you may want to try a thicker mineral oil. The V8 is old technology, the oil system is high volume rather than high pressure & isn't really suited to thin synthetic oils. Common topic of discussion on many of the Land Rover forums. Mine - 1986 RRC 3.5EFi - has been on mineral 15/40 since I've had it. Regular oil & filter changes are the key to longevity with these engines, failure to do so will result in the 'black death' of sludge in the engine.
What sounds like a rattle can also be an exhaust manifold gasket blowing. If you are using the individual gaskets - 8 of them - its very easy to fit them upside down & the wrong side out.

marksx

Original Poster:

5,052 posts

189 months

Tuesday 11th February 2014
quotequote all
At first I thought it was exhaust blowing noise, as I have heard similar from a previous RV8 I had.

However, it gets louder once the engine has warmed up. You can hear it when cold, but you can really hear it when warm. It is only there when under load. At cruise/idle I can hardly hear it, if at all. Temperatures are holding low and after 100 miles or so it hasn't lost any water.

Shame really, the body isn't that bad. Nothing I shouldn't be able to fix. Trust the expensive bit to be broken! That'll teach me to buy unseen from ebay!

EDIT - right bank, sounds like a heatshield rattling, that sort of noise. But it isn't. It sounds high on the engine/rocer area but that could be deceptive.

Edited by marksx on Tuesday 11th February 12:07

HarryW

15,150 posts

268 months

Tuesday 11th February 2014
quotequote all
manifold gaskets can make a metal ticking noise under load, almost a light pinking type noise?

marksx

Original Poster:

5,052 posts

189 months

Tuesday 11th February 2014
quotequote all
Would that get worse as the engine warms up?

HarryW

15,150 posts

268 months

Tuesday 11th February 2014
quotequote all
marksx said:
Would that get worse as the engine warms up?
I suppose it could do; as the blowing noise when cold goes to a tighter gap as it warms up and expands, closing it to a tiny gap that only blows (ticks) when the pressure is increased under load?
Worth a look/tightened up of header bolts at least?

paintman

7,669 posts

189 months

Tuesday 11th February 2014
quotequote all
Certainly worth a try & if you replace the gasket(s) on the one side & check the exhaust pipe to manifold gasket isn't blowing. Lot cheaper & much less work than doing the cam & followers!

marksx

Original Poster:

5,052 posts

189 months

Tuesday 11th February 2014
quotequote all
I like the idea of an easy fix!

I took a rubbish video to try and give you an idea.

http://www.youtube.com/watch?v=jucIWO6ZVOo

It doesn't convey the noise perfectly, it sounds more like a knock in the video, but you get the idea.

HarryW

15,150 posts

268 months

Tuesday 11th February 2014
quotequote all
Really don't know tbh. Sounds more like a coming together, exhaust on chassis due to engine mounts? Or the worlds slackest big ends!

camel_landy

4,863 posts

182 months

Wednesday 12th February 2014
quotequote all
HarryW said:
manifold gaskets can make a metal ticking noise under load, almost a light pinking type noise?
..and if you've got a split weld in the down pipe joints. wink

M

paintman

7,669 posts

189 months

Wednesday 12th February 2014
quotequote all
Sounds more like an exhaust system issue. Try going under the car & getting someone to rev the engine to see if you can narrow it down to a silencer or contact with something.

marksx

Original Poster:

5,052 posts

189 months

Sunday 16th February 2014
quotequote all
camel_landy said:
..and if you've got a split weld in the down pipe joints. wink

M
Top marks!



I'm still unsure as to whether this is the source of the noise. All manifold bolts and downpipe bolts are tight.

New video.





Edited by marksx on Sunday 16th February 16:03

marksx

Original Poster:

5,052 posts

189 months

Sunday 16th February 2014
quotequote all
camel_landy said:
..and if you've got a split weld in the down pipe joints. wink

M
Top marks!



I'm still unsure as to whether this is the source of the noise. All manifold bolts and downpipe bolts are tight.

New video.

http://www.youtube.com/watch?v=r_c2fRzQbac





Edited by marksx on Sunday 16th February 16:03


Edited by marksx on Sunday 16th February 16:08

camel_landy

4,863 posts

182 months

Sunday 16th February 2014
quotequote all
Oooohhh... That's sounding a bit rough!

Is that manual? If so, were they ever fitted with a dual mass flywheel (you can see where I'm going with this...)??

Another little trick you can use to help narrow down your search is to use a length of hose pipe; Use it like a stethoscope. With one end held to your ear, move the other end around the engine bay until you've found the source of your noise.

M

marksx

Original Poster:

5,052 posts

189 months

Sunday 16th February 2014
quotequote all
camel_landy said:
Oooohhh... That's sounding a bit rough!

Is that manual? If so, were they ever fitted with a dual mass flywheel (you can see where I'm going with this...)??

Another little trick you can use to help narrow down your search is to use a length of hose pipe; Use it like a stethoscope. With one end held to your ear, move the other end around the engine bay until you've found the source of your noise.

M
No, it's an auto.

I'll try the hosepipe trick. I can't get where I want to with a screwdriver but that should work.

Thank you