Diesel advice needed.

[robert m]

I just changed the timing belt on a 200tdi. Replaced all pushrods with new as 3 of the old ones were bent. The truck started just fine and drives but lacks power. Also there is what looks like steam coming out of the fuel filler tube and i can clearly hear a bubbling sound inside the fuel tank. Any ideas? Are the valve clearances so far out of adjustment by fitting new pushrod, that there is a lot of heated unburned diesel returning to the tank? Any help or suggestions would be appreciated.

[HeadDamage]

If you had bent push rods you could have other damage such as;

- damaged valves
- damaged rocker arms
- damaged rocker shaft
- damaged pistons
- damaged lifters
- etc...
- damaged injectors maybe depending on what happened


As for the bubbling my best guess is that you have air in the system and this would also result in power issues. Perhaps a really good bleeding of all fuel and injection lines would fix it.

[red90]

Did you adjust the valve clearance?? Timing set properly?

Diesel is normally returned to the tank as that is how the pump works. If it is bubbling there is air entering the system somehwere.

Can you hear the turbo coming on boost?

[JD]

A clear plastic fuel grade hose can be placed between the filter and injector pump that will show you if there is air in the fuel system. Air can make the injector pump clattery.

JD

[robert m]

Thanks everyone. There is no other evident damage. In fact, as the 200tdi is a 'no interference' engine, rarely is the damage more extensive than pushrods. The timing is adjusted as per the manual (not my first time) so should be fine, as for the valve clearances, will be adjusting these tomorrow. I am aware that the unused fuel is returned to the tank, but the vehicle ran fine before the pushrod change. Will check all connections to fuel pump and injector pump to see where it could be sucking air. I guess the valve adjustment will answer some questions. Love to hear more suggestions and ideas though.

[HeadDamage]

You might want to recheck the "no interference engine" thing ;)

[JD]

On a 300Tdi normal returned fuel is quite minimal. Perhaps, if the 200tid is similar, and your timing is out, a lot of very hot fuel (injector pump friction?) is being returned to the tank. Wonder where the heat is comming from. What doest the return pipe feel like when this is happening?

JD

[robert m]

Okay, HeadDamage, you are right. I should clarify.

A true non-interference engine is one where non of the valve components could come into contact with the pistons. The 200tdi and 300tdi do pose a small chance for some damage to occur. Even with the dished piston tops, there is an opportunity for a valve to contact a piston, which could in turn cause damage to lifters, guides, valves, and tops of pistons. Never heard of any bearings or con rods being affected unless they have been otherwise compromised. The non-interference or if I could correct myself, limited interference Land Rover engines only suffer minimal damage if any, due to the metal composition of the valve train components vs the push rods. As a safeguard and precisely for that reason the push rods are made of a much softer metal, making them the weakest link in case a timing belt breaks. Thus 90% of the time the only damage will be to the push rods.

That being said, I am about to recheck valve clearances, as one of the other forums did suggest the possibility of new push rods being a fraction longer, so valves never open/close for long enough, for all fuel to burn thus returning lots of unused fuel to tank and causing a slight loss in power.

Let you all know. Meanwhile more comments and suggestions welcome.

[JD]

Robert,

I've had a 300Tdi timing belt let go prematurely during 60Kph operation. It was a mess of broken lifters and bent valves. I suppose that could be considered "limmitted" but it sure didn't look or feel that way. The valves do make nice littlle ring marks on the cylinder heads.

JD

[robert m]

Thanks for that JD. Perhaps my information isn't as reliable as I thought ,as I personally have never experienced any such serious damage. I've had a belt snap twice, both times at slow rolling speed. Both times only bent pushrods.
As per the project at hand, adjusted valves which were waaaaayy out and the 200tdi now has much more power. The air in the fuel return line still bubbling away inside the tank. I suspect one of the injectors. When I crack open the lines on 3 out of 4, the idle goes down.... number 1 doesn't cause anything to change. So, now for another question... any idea how to free a stuck fuel injector? It just won't budge!!! And, the inevitable, does anyone have a 200tdi injector they want to part with?

[red90]

The 200TDIs are well known to only bend pushrods on timing belt failure. This is due to the valves hitting the pistons straight on and very weak pushrods. The design appears to be on purpose. The 300TDIs unfortunately suffer much more damage.

On the injectors, work them loose and check the spray pattern. 3 pipes free into containers and one injector hooked up. Crank the engine with the throttle fully open. You should see 5 clean radial sprays. Be caregul with them. The holes are VERY small. I should have a couple of decent used ones, if you need one.

I can't see how air gets in there, however. Air would (I assume) need to come in from the tank to the lift pump.

[robert m]

Thanks JD. Fitted new lift pump, still air bubbles..... I am about to attempt to take the injectors out. I suspect I will need one of your good used ones, so please let me know how to contact you. Thanks. [email protected]

[robert m]

Hay! Its fixed...... now we can all know what will cause tons of air to be returned to the tank.... it was an injector that was partially unscrewed. The 200tdi injector assembly comes apart into two halves revealing the contents.... two springs a nozzle and a bunch of washers and grommets. Turns out that if the two halves aren't tight, the injector sucks air, thus pushing it into the return line. Anyway, a bugger getting the injectors out but tightened all and the Defender runs like new.... Thanks all for your help! This was a weird one!