ianpittas Posted December 17, 2008 Share Posted December 17, 2008 hi ,my '86 3.5 efi now has the oil light coming on when on tick over after thr engine has been running for a while,the engine is a bit noisey and done 99000 miles,should i try a thicker oil as i dont know whats in it at the moment.also how difficult is it to change the oil pump gears with engine in situ.engine still has plenty of power but worried about the light a little. cheers ian Quote Link to comment Share on other sites More sharing options...
steve_d Posted December 17, 2008 Share Posted December 17, 2008 Snap. Mine is the same but I did the pump last year and run Halfords classic oil which is about as thick as it gets without finding something specialist. Pump is not difficult to do just remember to pack it with Vasaline when you rebuild it or the oil system will not prime. Have bought mine a 3.9 for Christmas. Steve Quote Link to comment Share on other sites More sharing options...
ianpittas Posted December 17, 2008 Author Share Posted December 17, 2008 Snap.Mine is the same but I did the pump last year and run Halfords classic oil which is about as thick as it gets without finding something specialist. Pump is not difficult to do just remember to pack it with Vasaline when you rebuild it or the oil system will not prime. Have bought mine a 3.9 for Christmas. Steve cheer's will give it a go.was looking on ebay at replacemnt engines but unsure on 3.5 or 3.9 as could buy one no better than mine,or to rebuild my 3.5. is a 3.9 a fairly straight forward drop in,a new ecu would also be needed? Quote Link to comment Share on other sites More sharing options...
jules Posted December 19, 2008 Share Posted December 19, 2008 I found when my old 3.5 efi 90 engine oil light started flickering on tick over it lead to the overall destruction of the engine on a 30 mile drive home from a play day. but a good remedy I found was the 4.2 I had sat in the garage also a noticable increase in power I have had mated chase round oil pressure problems for weeks and I found its much easyer to just change the engine with something you have tested and checked out before I found its cheaper and mush less time consuming. if you have the space I tend to buy a classic take what I want the floge the rest. Quote Link to comment Share on other sites More sharing options...
Gingerlandy Posted December 19, 2008 Share Posted December 19, 2008 hi ,my '86 3.5 efi now has the oil light coming on when on tick over after thr engine has been running for a while,the engine is a bit noisey and done 99000 miles,should i try a thicker oil as i dont know whats in it at the moment.also how difficult is it to change the oil pump gears with engine in situ.engine still has plenty of power but worried about the light a little.cheers ian Just a idea have you changed the switch with a new one as that may be at fault had a simliar problem with a old tractor and was just the switch. Quote Link to comment Share on other sites More sharing options...
paintman Posted December 19, 2008 Share Posted December 19, 2008 Change the switch. What oil are you using? Don't forget the V8 is ancient technology & running low viscosity oils & synthetic is not recommended. Quote Link to comment Share on other sites More sharing options...
plank22 Posted December 19, 2008 Share Posted December 19, 2008 cheer's will give it a go.was looking on ebay at replacemnt engines but unsure on 3.5 or 3.9 as could buy one no better than mine,or to rebuild my 3.5.is a 3.9 a fairly straight forward drop in,a new ecu would also be needed? yeh all is the same i think bar the odd hose or something, i have only changed from a 3.5 to a 3.9 in my series 3 so dont know about rangie but i can definlty tell you that the loom, ECU will need to be changed and the air flow meter will be different on the intake. The 3.5 has a flapper type system and the 3.9 has hotwire which is apparently loads better. If you do change get a complete engine, loom and ECU as geting them sperate and in one piece can be hard work! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 19, 2008 Share Posted December 19, 2008 Or ditch the stock ECU's and go megasquirt I'd agree with the comments above: - Try an oil & filter change - Try a new oil light switch (they do go faulty especially after being dunked off-road) - Beyond that I wouldn't spend the money on an old 3.5 lump really unless you absolutely can't stretch to a new engine. Bear in mind if it's not the pump it could be other more expensive things. Quote Link to comment Share on other sites More sharing options...
steve_d Posted December 19, 2008 Share Posted December 19, 2008 The 3.9 I'm fitting is the later serpentine drive and has an oil cooler in the rad so have had to source a rad as well. I don't know if all 3.9s are this way. Mine is also going Megasquirt. Had to make a new bracket for the coils as the front cover is a different design. I now have a spare bracket that fits a 3.5 or non-serpentine 3.9 if anyone wants it. Also have a chopped down dizzy I no longer need. Making new loom for the injectors Steve Quote Link to comment Share on other sites More sharing options...
jules Posted December 20, 2008 Share Posted December 20, 2008 Going a bit off topic but I always use a oil cooler on my V8's In my challenge truck I used a Defender TD rad has a oil cooler in it as do most of the late classic rads. Quote Link to comment Share on other sites More sharing options...
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