White smoke / Unburned gas smell After Engine Overhaul

[reym]

SOS guys,

My brother has an owner type jeep with a toyota gasoline engine.
He let a shop do the overhauling on his engine.
The camshaft was regrinded, replaced all bearing, placed sleeve, change piston rings, changed valve seat and seals, regrind valves.

Day 1 - Engine is too rough, difficulty in going over a hump. (still managed to at high rpm)
Day 2- Engine still rough (at idle up to 1000 rpm) but has more power, going over a hump is less difficult, engine has no smoke at idle but smokes at more than 1000 rpm (white smoke), exhaust has a smell of un burned petrol.
Day 3- Engine stalled, carb was blocked with something, forced to get home adjusted idle at 2000 -2500 rpm (20 mins drive).

Day 4.- Engine still rough (at idle up to 1000 rpm), power did not improve ,still smoking and un burned petrol fume is still evident from exhaust.

Average daily drive = 5 km per day.

Note: Mechanic did not clean the exhaust pipe.

Any Ideas ??

[speedyfix]

obviously something wrong with the overhaul. in cases like this you should really ask the shop who did it what is wrong with their own work.

[KBR]

SOS guys,

My brother has an owner type jeep with a toyota gasoline engine.
He let a shop do the overhauling on his engine.
The camshaft was regrinded, replaced all bearing, placed sleeve, change piston rings, changed valve seat and seals, regrind valves.

Day 1 - Engine is too rough, difficulty in going over a hump. (still managed to at high rpm)
Day 2- Engine still rough (at idle up to 1000 rpm) but has more power, going over a hump is less difficult, engine has no smoke at idle but smokes at more than 1000 rpm (white smoke), exhaust has a smell of un burned petrol.
Day 3- Engine stalled, carb was blocked with something, forced to get home adjusted idle at 2000 -2500 rpm (20 mins drive).

Day 4.- Engine still rough (at idle up to 1000 rpm), power did not improve ,still smoking and un burned petrol fume is still evident from exhaust.

Average daily drive = 5 km per day.

Note: Mechanic did not clean the exhaust pipe.

Any Ideas ??

yikes, well.. did you guys do a proper Break-In procedure on the motor?? coz if the motor is not properly broke-in, chances are that the Piston Rings are not seated yet (and hope that your "mechanic" put on the Piston Rings in their right position (the piston ring end gap location on the Piston) before putting it in the block. coz if the rings are not set on the right position, that is asking for a possible "blow by" which is not good at all.

also, if the Camshaft is re-grinded, is it "re-grinded" in the proper specs? and is it "re-grinded" to stock specs or as an upgrade? coz if they re-grinded the Cam to have more Lift & Duration, chances are that you are really going to have a lumpy Idle (just like a stage 2,3,4, etc.. High Performance Camshaft(s).. w/ higher Lift & longer Duration which will produce a lumpy idle at lower RPM's). and also, did they replace the Valve Springs?? (and hope they checked the height of the stock Valve Springs, coz if the stock valve springs are no longer in specs, your valves will just float and it will not open and close at the right distance and it wont let the Valves seat properly as well (which all can cause rough idling and hesitation).

also, check your timing.. make sure that the Spark Plugs, Wires, Cap & Rotor (all the good basic stuff) are replaced.. and make sure the Distributor is lined up at the right position (TDC or BTDC.. refer to your repair manual). and check the Carbs as well.. (but check the timing and ignition system first.. since that you might have adjusted the carbs too much, which is probably running too rich at this point.) .. and check for Vacuum leaks too.

anywayz, hope these simple tips/advice would help.. and hope your engine runs the way it supposed too soon!


aite, peace.

[reym]

Thanks guys,

The camshaft was not re-grinded, only the crankshaft journals are regrinded.
I doubt that the springs were checked for proper tension. As far as the block components, i think they have done it well. The cylinder head was sent to another machine shop for overhauling.

Update: Ive checked the sparkplugs after 80kms and the is barely a carbon buildup in it. I checked the oil level and 1/4 of a quart is missing.

I have observed that the idle is rough while it is cold, after 30 minutes of driving the roughness lessens.

If I stop the engine and let it cool for just 5 minutes, it idles like hell again.

[speedyfix]

the valveseals may not have been lapped properly

[reym]

the valveseals may not have been lapped properly

Thanks sir speedyfix

may corrections lang ako : 1 quart pala ang nabawas na langis.

sir ano ba name mo tatawag ako sa office mo.

[speedyfix]

look for either me (migs) or my chief mechanic reynante.

[fireblade]

look for either me (migs) or my chief mechanic reynante.

Cant go wrong with speedyfix, very good reputation here in tsikot

[reym]

Update: I had a the compression check last satuday the values are:

1. 110
2. 110
3. 110
4. 120

The oil consumption seem to go away after 150 kms. But the unburned smell and the shaky idling persists.

[yebo]

na check na ang ignition timing? how about the high tension cables, baka naman merong putol? these can also cause rough idle and loss of power.

[reym]

na check na ang ignition timing? how about the high tension cables, baka naman merong putol? these can also cause rough idle and loss of power.

Thanks

I am not familiar with electronic Igniter, so sa dwell angle na lang ako nagbase, pag nag advance pa ako kahit konti eh nag piping (parang may kumakatok), pag nagbawas naman ako ng kahit konti para namang lalong gumagaspang.

Sa wires di pa ako nag check, subukan kong palitan this week.

[speedyfix]

the compression test results seem on the low side.

[4JGtootsie]

Questions lang to help us evaluate your engine problem.
Why did you overhaul?
Condition of the piston? Ring/groove clearance? Standard or oversize?
Condition of cylinder walls? Was it measured? Did honing? Pattern?
How did you do the break in?

[eyshmechanic]

ano ba ang original problem why resulted to overhaul?
please check pcv baka barado na. it is typically located sa crankcase cover. the symptoms you mentioned e parang kulang sa hangin na pwedeng coz of baradong pcv.

[reym]

Questions lang to help us evaluate your engine problem.
Why did you overhaul?
Condition of the piston? Ring/groove clearance? Standard or oversize?
Condition of cylinder walls? Was it measured? Did honing? Pattern?
How did you do the break in?

Well I bought the jeep as is, not running, for a very cheap price, when the engine was started it is killing sparkplugs.
Plus there is a knock sound when the engine is cold.

When the head was separated from the block, we noticed that #4 ring is broken,
the piston is still in its standard size, all the bearings are worn out, even the thrust washer was worn.

The break in procedures:

1. I run the engine at 1,500 rpm for 10-20 minutes,
2. Drove it like an old lady for 20 kms.
3. Drove it at 30-50 kms per hr with slow acceleration and quick decel for a max of 20 kms
4. Drove 80 kms with speed of 20-60km on NLEX, with occasional decel.

[4JGtootsie]

Ok naman ang break in.
Now specifics naman.What is your engine?
Carburated? EFI?

[reym]

Toyota 4K
Carb engine
Contact Points

May drag sya from stop hanggang marelease ang clutch
Fuel mixture screw is not affecting the idle.

Nagkaroon sya konting improvement nung tingangal ang igniter at pinalitan ng contact points.

Kanina medjo may drag pa rin, pero parang malakas ang response ng makina kaysa nung mga unang araw.

May napansin din ako, nag load balance test ako sa 4 cylinder 1 week ago, mahina ang #3 cylinder, kahapon malakas na ung #3 pero mahina naman ang #1, epekto kaya ng pagpapalit ng distributor un?

[eyshmechanic]

subukan mo bunutin yung hose sa pcv and see what happened.

[darksword_08]

dude

nabreak-in ba yan ng maayos?
a good break is having the engine running for 1-2 days w/o using it to go to other places,,

pinalitan mo piston ring, sleeve, bearing and others

gamitin natin ung term na "hindi pa lapat ung piston ring mo" and other parts

kaya need nyan ng good break in,, di pa yan dapat itakbo

kasi since hindi pa umaakma yung parts nya with one another

kung pwede nga hindi dapat uminit makita mo

sa diesel engine ang pinapagaw namin pag new overhaul 1 week break-in na umaandar lang engine sabay buhos ng tubig para di mareach yung specific heat level if nagawa ung good break in yun,, hindi din dapat nirerebolusyon,bad yun for the engine

in your case 4k engine mo,, we requies for the break-in continious running water from hose to radiator to keep the temperature low as possible

di mu pwede buhusan ng tubig yan mamamatay makina..


maybe nafry agad ung pisto ring mo at damage agad sleeve kaya may amoy sunog na langis

piston ring avoid the oil from reaching the top cylinder so that no fumes are created,, if the oil reaches the top cylinder and mix with the gas it will sure create that effect

or the mechanic did not notice the proper alignment or setting a piston ring leaving space for the oil to pass through

lets hope na di nasira ung parts na pinalitan mo,, or else overhaul uli yan

and try to give it a good break-in

about sa regrinding ng camshaft my cetain clearance sinusunod mga machine shop in doing that.. lagi sila ngbase sa size ng bearing na lalagay mo,, they will not grind something na hindi akma sa bearing or else the engine will lost its compression which is important for ang engine to have

[afrasay]

baka di natapat yun timing mark ng maige.