300tdi electric fan?

I recently did a conversion putting a 300tdi into a TD90, and put a series III front end on. Therefore there is no space for the standard cooling fan behind the radiator and intercooler. I fitted a Nissan Pajero electric fan in front of the rad but have been getting overheating problems. Is the fan sufficient to do the job?

It should be, as a number of the guys run theirs with no fans at all, or leccy fans on a separate switch which they barely turn on.

Is the rad hot across? Not uncommon for them to block, so cold spots worth checking for.

If Rad all over, check top hose is hot (if not thermostat not opening) and for any airlocks

Which way is the fan blowing?

The fan should be drawing hot air FROM the radiator, not blowing cold air into it.

Matt TDi said:

Which way is the fan blowing?

The fan should be drawing hot air FROM the radiator, not blowing cold air into it.

Click to expand...

But if the fan is in-front of the rad then it HAS to push cool air into it, it is not ideal but should work quite well.
I ran my S111 SWB V8 with a pusher fan for the same reason (no space between front of engine & rad) and that worked fine.

I take it that it is definately pushing the air into the rad and is not trying to go against the natural through-flow as the vehicle is moving?

Airflow from fans is at its most efficient when drawing the hot air from the radiator, not blowing cold air into it.

There will be a big deficiency in heat exchange if a fan is installed to blow cold air through, rather than draw hot air from.

I'm not saying that a blow through design doesn't work, I'm saying it's not as efficient. If the system is suffering from cooling problems, especially when stationary or at low speeds (ie off roading) and has had the cooling system altered, which this has, the afforemention issue needs to be considered, amongst others mentioned.

Agreed not as effecient but if he has been forced into that set-up then there is no reason why it shouldn't work.

Personally I would say it is not a fan issue anyway as a correctly functioning cooling system on a 300TDi will not call for the fan 98% of the time so the fact it is overheating and the fan can't cope points towards something else. If your engine (talking TDi here) will only keep at the correct temperature with the fan running all the time then there is an underlying problem that needs to be rectified.

You say it is a conversion so I take it that it is definately getting too hot and it isn't just a sender / gauge mismatch?

And what radiator are you actually using?

Pete here. The landy has a brand new Britpart 300tdi rad, which only gets hot around the entry point of the pipes. The fan is in front of the rad, blowing cold air through onto rad. Have fitted 2 new 300tdi thermostats, a new reconditioned head, and bled the sysytem to death! All of this should work and I'm wondering if the whole engine was shagged before I put it in- There have been overheating problems from the word Go, which have recently got a lot worse (5 minutes at gentle speed on normal road and she was dangerously into the red). The engine was bought in good faith, but the frost plugs were blown. Thanks for advice so far.

sounds like poor rad ,they fill and empty on the same side , if its not hot all over change it

Peter Compton said:

Pete here. The landy has a brand new Britpart 300tdi rad....

Click to expand...

That'll be your problem then Pete

Horribly ****e components from BP (In my opinion)

I trust you've completely flushed the engine? Crud & corrosion from years of neglected antifreeze changes can easily block up coolant galleries.

Hi Matt, Excuse the newbie ignorance but how would I flush the engine coolant galleries? The Brit Part rad was fitted after the cooling problems started getting v bad, we still have the original tdi rad that came with the donor vehicle. It was scruffy but seemed ok. There was a lot of rust in the enigne waterworks...

it is an easy check .wouldnt worry too m uch about flushing ,run engine till hot .if top hose is hot thermostat is open and rads should be hot all over if it isnt change it,if its new send it back

I would be surprised if the thermostat is open within 5 minutes at gentle speed in this temperature, my heater is only just getting warm after 5 minutes.

When you say it overheats what actually happens?

BP one was fitted after the cooling probs started, as an attempted remedy. We started with the original 300tdi rad from the donor vehicle (still in the shed). There was a lot of rust in the coolant water exit points from the engine. How should we go about complete flush of coolant galleries? Excuse the newbie question please.

Like I said in my earlier post, is the engine ACTUALLY overheating or are you just relying on the gauge?
Has it EVER run at the correct temperature?

I'm guessing that the rad fan is kicking in (hence the question about the fan originally) but not cooling the engine.

First step is check the radiator temperature all over as advised.

If that's okay, then do a complete coolant flush. You can buy specific flush for this, I know Wynns and Tetrosyl do one. All you do is add it to the coolant and go for a spin. The flush will remove all the crap that may be blocking some of the galleries up. You then just flush the whole system through for a few minutes with clean straight water from a hose pipe to remove all crap until the water runs clean. Then top up with water and antifreeze at whatever mix you feel necessary.

What sender did you use tdi or td?

The sender was on the engine already, and have been told it is the right one. The whole engine gets far too hot, the hoses are all scalding as well. We have checked the waterpump, it's sound. Water moves freely through the rad when you squeeze the hoses, and filling the header pushes water out the top bung hole on the rad. Is there anything that can go wrong deep inside the engine? A mechanic friend reckons that it could be cracked cylinder linings/ other piston problems.:doh:

if bore was cracked as they dont have liners ,you would have locking on starting ,pressurised cooling system with coolant coming out of cap,there not pronr for clogging up in the block unless run on water for years have you actually felt rad ,if baffles fail water drops stright through on top hose side ,if it is getting hot either rad (biggest fault ive found) thermostat ,water pump or leakage from p gasket ,cracked head ,hoses etc or not filled correctly