4a question, running on 2 cyl, damaged valves???

[JoJo]

hey guys,

I just thought i would get some opinons before i rip the engine apart or toss it out altogether..

My question is:

What would be the symptoms of broken/damaged valves in a 4A?



The story:
I was driving my 4a (in good cond, 280,000km, reg serviced) to work and i was just driving granny style (60kph) when suddenly lost engine power and it began to 'rattle' when i was to rev it. I pulled over..


After limping the car home, and inspecting the engine, this is what i have noticed.......

1. Only running on 2 cyl (cyl 1 and 2 NOT WORKING)
2. Spark to all plugs is ok
3. No engine rattle on idle or slow gradual revving BUT rattles when you give it a sudden rev.
4. Engine DOES NOT blow any smoke (fuel or oil) but exhaust smells very 'fumey'
5. Headgasket???? Water is perfect, no sludge etc..... Oil looks fine........
6. Idles smoothly (for only running on 2 cyl)

Any ideas?

I was thinking the valves but i havent delt with damaged ones before.............


thanks

J Riftin

[fixeruperer]

prolly blown head gasket between 1 and 2, do a leak down test on them and see were the air is going.
then go form there

[2jzhilux]

if it does it under load you may have spun a big end bearing but it depends what type of sound it is .

[MRMOPARMAN]

if it was a big end bearing, it should be making the rattle all the time, and should be making it run on 2 cyls.

ill 2nd the leak down test. or even if ya connect pressurised air to each cylinder (on tdc firing for each cylinder pressurised) when pressurised, if theres something wrong, you'll hear air pissing out of different places. when pressurised...
1. open the oil breather and listen for major air leakage = rings/pistons/headgasket-unlikely

2. disconnect the intake hose, open the throttle body wide open and listen for major leakage = inlet valve/seat/not on firing tdc

3.listen for major leakage at the tailpipe = exhaust valve/seat/not on tdc firing

4. if pressurising no1 cyl take out no2 spark plug and vice versa, listen for major leakage through opposite spark plug hole = headgasket/head

5.take radiator cap off (carefully) = headgasket/head.

^ this would be much more accurate if you had a leak down tester, as you can tell how badly its leaking air. but just pressurising works for a bush whacker method

my vote is for cracked ring land or gudgeon.

btw.. you checked the ignition system (eg cap,plugs etc) and the injector pulse etc didnt you? is it a bigport? if so check the throttle body butterfly grubscrews. ive had one go fall out and go through no4, and it made sounds similar to what your experiencing.

[thu187]

The story:
I was driving my 4a (in good cond, 280,000km, reg serviced) to work and i was just driving granny style (60kph) when suddenly lost engine power and it began to 'rattle' when i was to rev it. I pulled over..

3. No engine rattle on idle or slow gradual revving BUT rattles when you give it a sudden rev.

if it was a big end bearing, it should be making the rattle all the time, and should be making it run on 2 cyls.

When I spun a bearing I initially just had rattle about halfway through the rev range and when I gave it a sudden revving. Same thing happened to me I was driving along pretty sedately then bam lost power and grandpa'd it home. Later on it started rattling all the time but yeah initially it was ok with gradual revving. Just thought I'd add my bit of input.
Were you using Castrol oil by any chance?

[oldcorollas]

if you don't have tools at your disposal...
you can do a simple kind of leak down test to see if something is really fubar..

just turn engine by hand. you should feel the resistance of each piston going up every 180 degrees.
if you can turn two complete revs and all "compression thingies" feel the same, then maybe the compression is still partially there.

if you turn over twice and you only feel 2 compression events, then something is rooted.

you say 1 and 2.. and firing order is 2134, so if 1 and 2 have mechanically lost all compression (or most), then 1 of the two revolutions will have little resistance...

also, pull the spark plugs and look for damage on them and on the top of the piston (use torch)

next simple step is to pull the cam covers off.. rotate engine and check all valves return to the same height when off the lobe..... and look for signs of damage on buckets and shims

[Cuzzo]

if you don't have tools at your disposal...
you can do a simple kind of leak down test to see if something is really fubar..

just turn engine by hand. you should feel the resistance of each piston going up every 180 degrees.
if you can turn two complete revs and all "compression thingies" feel the same, then maybe the compression is still partially there.

if you turn over twice and you only feel 2 compression events, then something is rooted.

you say 1 and 2.. and firing order is 2134, so if 1 and 2 have mechanically lost all compression (or most), then 1 of the two revolutions will have little resistance...

also, pull the spark plugs and look for damage on them and on the top of the piston (use torch)

next simple step is to pull the cam covers off.. rotate engine and check all valves return to the same height when off the lobe..... and look for signs of damage on buckets and shims

Isnt the firing order 1 3 4 2?

Get your self a compression tester. Even borrow one from someone. It helped me decide i needed to remove the motor. Piston 3 cracked ringland.

[EldarO]

it is 1 3 4 2, same as 2T too.

[oldcorollas]

Isnt the firing order 1 3 4 2?

Get your self a compression tester. Even borrow one from someone. It helped me decide i needed to remove the motor. Piston 3 cracked ringland.

1342...134213421342134"2134"

but since the problem cylinders are 1 and 2, it seemed easier to group them in the firing order because then i wouldn't have to waste time explaining that 2 comes befre 1 in the firing order of 1342, and that you should be looking for consecutive compression events not happening

[JoJo]

It is a 4A (SOHC, carby fed), NOT a 4AGE.......

[JoJo]

When I spun a bearing I initially just had rattle about halfway through the rev range and when I gave it a sudden revving. Same thing happened to me I was driving along pretty sedately then bam lost power and grandpa'd it home. Later on it started rattling all the time but yeah initially it was ok with gradual revving. Just thought I'd add my bit of input.
Were you using Castrol oil by any chance?

This sounds exactly like what happend....

[Grega]

same as above applies for teh 4age, just minus a cam ect. i'd say HG blown between 2 cylinders by what u describe

[lexsmaz]

Start it up with the air cleaner off & give it a rev, if it starts to pop, & you can feel air start to come back through the carby, i would suspect as the others have said it has a blown gasket between # 1 & 2 cylinders ..Easy quick check if you know what you are looking for ..

[JoJo]

PLUGS - Drity, but not damaged
IGNITION - Fine, has spark
CAM COVER OFF - Valve springs, cam etc, look fine
WATER - Looks perfect,
OIL - looks ok


Some people say headgasket. If it was, whats the rattle when sudden revs applied?

[oldcorollas]

hand turning of the engine resulted in?