recon engine not running properly

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2005lyndon

New Member
Posts
50
Location
stafford
ive just installed a recon unit in my p38, its a 4 block that has been fitted with 4.6 crank, pistons etc, heads skimmed pressure tested etc, and put back together by the mechanic, i just nailed it in!
since re instalation and very few miles 20 or so, the engine starts nicely, sounds wuite, but gets progressivley rattly, and a small misfire appears, ive had the plugs out, and 2,4,8 seem oily,6 is a little oily the rest look fine, so i cjanged the leads and plugs, and the misfire, which seems to get worse when warm is still there, plus the engine lacks any go, and sounds like an old granada when warm, thre is also a lot of blue smoke when pulling off, which clears after a run, top hose also goes hard but not solid
as the previous/old engine blew its gasket on this side could the lambda sensor be at fault or possibly a coolant sensor? but that doesnt explain the rattly noise when warm, havent done a comp test yet, but obviously thats the next step
the mechanic wants to check the engine installation over before expressing an opinion, i want to make sure i have everything checked, before it goes back as its a long way, and a lot of work i havent got the heart for at the moment, failing that anyone want to buy a fsh 96 "p", 83k 4.6hse

cheers
lynd:mooning:
 
im in staffordshire, its to go to lancashire,78 miles away we have just sold our other tow vehicle, and i dont fancy driving it, and causing further damage.
the compression test should start to make things clearer, anyone know what is hsould see compression wise for a "fresh" engine

thanks
 
ive just installed a recon unit in my p38, its a 4 block that has been fitted with 4.6 crank, pistons etc, heads skimmed pressure tested etc, and put back together by the mechanic, i just nailed it in!
since re instalation and very few miles 20 or so, the engine starts nicely, sounds wuite, but gets progressivley rattly, and a small misfire appears, ive had the plugs out, and 2,4,8 seem oily,6 is a little oily the rest look fine, so i cjanged the leads and plugs, and the misfire, which seems to get worse when warm is still there, plus the engine lacks any go, and sounds like an old granada when warm, thre is also a lot of blue smoke when pulling off, which clears after a run, top hose also goes hard but not solid
as the previous/old engine blew its gasket on this side could the lambda sensor be at fault or possibly a coolant sensor? but that doesnt explain the rattly noise when warm, havent done a comp test yet, but obviously thats the next step
the mechanic wants to check the engine installation over before expressing an opinion, i want to make sure i have everything checked, before it goes back as its a long way, and a lot of work i havent got the heart for at the moment, failing that anyone want to buy a fsh 96 "p", 83k 4.6hse

cheers
lynd:mooning:

Checking the engine installation won't cure the oil burning. That is either down to valve stem oil seals/badly worn valves/ guides or piston rings. Did he bust the bores before fitting pistons. Did he fit new rings. Did he check valves/guides for wear, did he fit new stem seals. You just nailed engine in, sounds like he just nailed it back together. Good way of checking valve stem seals, go down a steep hill with throttle closed, if when you open it up it smokes, oil is being sucked in past seals.
 
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ive managed to check everything back again ,today and the new plugs have fouled exactly the same as before, 2,6,8,3 , are oily/wet/carbon, the others are showing as lean and fine
so i have done a compression test,
what pressure should i expect to see, ive done them "dry" then did a wet test, from memory as ive left my notes with the vehicle,the pressure varied form 200(no2)-152(no8) dry, and 210(no2) to 165(no8) "wet"
1,3,5,7, were all much closer to each other wet and dry, from memeory around the 160's
the other thing that niggles me is the intermittent blue smoking after ticking over, but that clears after a run, also that when it starts it sounds nice and smooth, but when warm it starts to sound rattly
ive a mechanic coming to look at it tommorow, time alowing he will do a leak down test as i dont have the equipment, it didnt seem to smoke, going down a steep hill off throttle,
just to recap its a 1996 4.6, any info on the compression figures would be great

thanks
lynd
 
ive managed to check everything back again ,today and the new plugs have fouled exactly the same as before, 2,6,8,3 , are oily/wet/carbon, the others are showing as lean and fine
so i have done a compression test,
what pressure should i expect to see, ive done them "dry" then did a wet test, from memory as ive left my notes with the vehicle,the pressure varied form 200(no2)-152(no8) dry, and 210(no2) to 165(no8) "wet"
1,3,5,7, were all much closer to each other wet and dry, from memeory around the 160's
the other thing that niggles me is the intermittent blue smoking after ticking over, but that clears after a run, also that when it starts it sounds nice and smooth, but when warm it starts to sound rattly
ive a mechanic coming to look at it tommorow, time alowing he will do a leak down test as i dont have the equipment, it didnt seem to smoke, going down a steep hill off throttle,
just to recap its a 1996 4.6, any info on the compression figures would be great

thanks
lynd

Main thing about compression test is that they are all within around 10 psi of each other. Or you will have an engine that runs like a bag of spanners.
Sorry to be negative but it sounds like he has made a real mess of rebuild.
If you do a comp test first of all do it dry and record all values. If for instance one is lower than others by a fair bit (see above) put a squirt of oil in the bore. If pressure rises it is the rings if it stays the same it is the valves. From your test looks like he did not fit new rings then?
 
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yep i did the "dry" test first, and thats where the lower figures turned out, the thing that was consitent with the wet test was the poor performing ones improved correspondingly, but still remained poor
when i get to the vehicle tommorow i will post the comp figures, and gauge the audiences opinion if the differential is accepatable, across the engne the highs and lows or close to 24%, which doesnt sound right,

will see what prognosis of independent mechanic is tommorow

thanks
 
yep i did the "dry" test first, and thats where the lower figures turned out, the thing that was consitent with the wet test was the poor performing ones improved correspondingly, but still remained poor
when i get to the vehicle tommorow i will post the comp figures, and gauge the audiences opinion if the differential is accepatable, across the engne the highs and lows or close to 24%, which doesnt sound right,

will see what prognosis of independent mechanic is tommorow

thanks

As i said before if the bores were busted and new rings fitted. Valves removed and reground. I would think from memory you should expect 180 + psi all within 10 psi of each other. The blue smoke is more than likely knackered oil control rings, sounds like he just threw the pistons in as they were. It just depends what you paid him or wanted him to do. Personally i would not do that even if told to, it is bad practice.
 
would it be wuth considering the gaps in the rings are all in line not at 3rds allowing oil up the bores ?

I think that is the least of his worries. Placing worn rings from one engine into glazed bores on another engine is not the best way forwards. The mechanic should have at the very least busted the bores and fitted new rings. If he did bust the bores and fit new rings someone has a bigger problem than ring gaps lined up.
 
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