Is it time for a rebuild?

Hi there,
My Discovery 200Tdi automatic with 300,386 K on the clock had always started on the button until now.
For about a month or so now, it cranks over for about 3 to 5 seconds or sometimes more before firing into life every morning.
Before anyone mentions the glow plugs, the car is located in the tropics with average ambient temperatures of 30 degrees C, plus the engine has always started up fine without them in the 9 years since the relay failed.

Anyway, throughout the course of day, it would always start right up until its parked for more than 5 to 6 hours at a time, then again it would take a few seconds to turn over before firing up.
Thing is, although it doesn't put out perceptible oil smoke, it does use a bit of oil (about a quart every 1K), and have noticed a mist/vapor pouring out of the crankcase breather when the engine warms up.
Aside this mist, it does not blow out pressure from the top when the oil filler cap is removed.
It does not use any water, and performance has not been affected in the least. It still pulls hard, and is able to maintain a steady 70 on the highway.
I have replaced all fuel filters but that has not made any difference at all.
It seems to be getting more and more difficult to start up with each passing day, and I'm wondering if its on account of maybe the engine being worn and being a tad bit low on compression and needing a rebuild.
What do you guys think?

Time to replace some pipework firstly, leak off pipes to the injectors are made of rubber usually and perish allowing air in, this then allows the fuel to drain back to the tank but I'd check all your fuel pipes for starters Or better still pay me to come and do it for you

Marmaduke said:

Time to replace some pipework firstly, leak off pipes to the injectors are made of rubber usually and perish allowing air in, this then allows the fuel to drain back to the tank but I'd check all your fuel pipes for starters Or better still pay me to come and do it for you

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Marmaduke, it's a tad bit early in the year to think of going on vacation, isn't it?

ifloochies said:

Marmaduke, it's a tad bit early in the year to think of going on vacation, isn't it?

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Er no, is it snowing in Ghana?

Marmaduke said:

Er no, is it snowing in Ghana?

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No Sir, it most certainly is not!!!

ifloochies said:

No Sir, it most certainly is not!!!

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Well there you go then, shall I start packing?

Usual answer is to remove the fuel filter if its not brimming with diesel it needs a lift pump.

Marmaduke said:

Well there you go then, shall I start packing?

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Kindly wait here, let me go mow the lawn, fix the leaky sink, vacuum the rug, oil the squeaky gate hinges, replace the burnt out porch light.........and then I shall have earned enough points to ask SWMBO's permission!!!

lynall said:

Usual answer is to remove the fuel filter if its not brimming with diesel it needs a lift pump.

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I have one of those see-through filters installed on the suction line from the tank, right before the lift pump, and that's always full of diesel. Question is, if the lift pump was dead/dying, would it not affect engine performance somewhat? Other thing is that, by working the priming lever on the lift pump, there's a bit of resistance at first as I see it move fuel through the filter, and then it goes soft, I suppose when the filters and FIP are primed, is that about right/normal?

ifloochies said:

I have one of those see-through filters installed on the suction line from the tank, right before the lift pump, and that's always full of diesel. Question is, if the lift pump was dead/dying, would it not affect engine performance somewhat? Other thing is that, by working the priming lever on the lift pump, there's a bit of resistance at first as I see it move fuel through the filter, and then it goes soft, I suppose when the filters and FIP are primed, is that about right/normal?

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I'd say it might be the injection pump throttle shaft seal, if it is leaking it allows fuel out of the body/gallery of the IP to siphon back to the tank via the excess fuel return line, strange though it may seem it does not noticeably leak fuel to the outside on to p of the pump. To rule that seal leak out, fill the fuel tank full and parkyour vehicle overnight nose down, ie raise the rear up hill, (easy if you have a sloping driveway like mine), but it does not have to be a great slope. If in the morning or whenever you have to start your vehicle after a long stand the engine buttons away as it does the rest of the day, you have found the problem.
The shaft seal is only an 'o' ring, small and cheap, ($1.00 here in Aus), it is relatively easy to fit, there are a few posts here on how to do, just do a search.
The symptoms you describe are exactly as my Disco Tdi displayed a few years back, new seal did the trick and fixed the starting after overnight problem.

ifloochies said:

I have one of those see-through filters installed on the suction line from the tank, right before the lift pump, and that's always full of diesel. Question is, if the lift pump was dead/dying, would it not affect engine performance somewhat? Other thing is that, by working the priming lever on the lift pump, there's a bit of resistance at first as I see it move fuel through the filter, and then it goes soft, I suppose when the filters and FIP are primed, is that about right/normal?

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If its full I reckon you are good to go.
Ive had a couple of lift pumps fail and yes it does effect power but only at the top end, the FIP also has its own internal lift pump built in and on lots of other vehicles the VE FIP is used on there is no extra external lift pump.
On mine I binned the lift pump and fitted a facet unit, makes filter changes and running out of fuel a doddle!

So spent the past day and a half going over my fuel system, front to back. Gone over everything, and everything seems to be in order. No leaks, no perished hoses, loose connectors or anything of the sort. @Gazbo , about the FIP, mine had a slight leakage at the joint between the top cover and pump body, so took the opportunity to replace the O-ring on the throttle control shaft when I was in there replacing the gasket about a month or so ago. I can say for certain now that I have no fuel leaks anywhere as far as I have checked. Had the car parked since Thursday afternoon, went to prime the fuel lift pump before starting it yesternight, and filters were already full of diesel. The priming lever moved once and went soft because everything was already filled with fuel, yet it took some cranking to get it going. Anything else I should be looking at?

ifloochies said:

So spent the past day and a half going over my fuel system, front to back. Gone over everything, and everything seems to be in order. No leaks, no perished hoses, loose connectors or anything of the sort. @Gazbo , about the FIP, mine had a slight leakage at the joint between the top cover and pump body, so took the opportunity to replace the O-ring on the throttle control shaft when I was in there replacing the gasket about a month or so ago. I can say for certain now that I have no fuel leaks anywhere as far as I have checked. Had the car parked since Thursday afternoon, went to prime the fuel lift pump before starting it yesternight, and filters were already full of diesel. The priming lever moved once and went soft because everything was already filled with fuel, yet it took some cranking to get it going. Anything else I should be looking at?

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Looks like you've covered it pretty thoroughly, if possible I would recommend, if you have not already done it, to try the "nose down" parking thing with a full tank of fuel.
I had been through everthing on the fuel system, EXCEPT , the top section of the IP, simply because it showed not a sign of a fuel leak to the external, but it was still leaking air back, causing the starting problem.
Maybe another thing you could do is, before trying to start the engine after a long time standing, lift the bonnet and crack one of the injector union nuts and crank the engine, see if air or fuel are immediatly produced.
This should rule in/out absolutely the absence of fuel as the problem.

Turns out the old engine had just about had enough....compression test confirmed it.

Only two things will stop the tdi starting - lack of fuel and lack of compression. The glow plugs are only there for show!

zeaphod said:

Only two things will stop the tdi starting - lack of fuel and lack of compression. The glow plugs are only there for show!

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Too true.... I guess I was expecting too much of the old engine when I hoped she would run forever I know other 200Tdis have done bigger miles, but being a daily drive for the past 8 years with over 300K on the clock is pretty respectable.....old lady never skipped a beat in all that time. I'll find the time soon and do her proud with a rebuild.

It's amazing what new rings do for the engine. Mine fires straight up every time I don't even use the glow plugs. At 300k id be pretty damn proud of that engine!

IamRobbie said:

It's amazing what new rings do for the engine. Mine fires straight up every time I don't even use the glow plugs. At 300k id be pretty damn proud of that engine!

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I am Robbie, I most certainly am.....now to find the time for the rebuild within this decade.

ifloochies said:

I am Robbie, I most certainly am.....now to find the time for the rebuild within this decade.

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It's pretty straightforward once you get into it. I'd never done anything of the sort before but managed to do it myself over a small period of time bit by bit. Such a good feeling when it fires up after being put back together