Toyota diagnosis help needed.

[70herald]

After 11 years of ownership, and lots of competition from the Triumph, seems like the Toyota wants more attention.

At the beginning of the summer, I had overheating problems on the highway, replacement of the thermostat seems to have solved this.

Now it has developed a new issue which may or may not be related. Under hard acceleration or light acceleration at higher speeds, there is severe pinging or some other noise almost as if I had a leak suddenly at the header letting up on the gas pedal and it goes away. In addition, at the same time, it started heating up again but this time at lower speeds than before (I was at a maximum of 50mph)

Listening to the engine when I raced it (parked) it seems that the noise is coming more from the back, (intake manifold side) than the front side (exhaust)

The car has just over 60,000 miles. Any ideas? would failure of the O2 sensor cause it to go lean? could it cause overheating or pinging? It has a distributor, but timing is electronic.

The car has the 4E-FE engine, which seems to be basically a smaller version of the pre-94 Tercel engine in the US.



To make maters much worse, I went to take the cover off the timing belt to make sure it hadn't slipped, and dropped one of the blasted bolts into the engine :madder: :madder: :madder: :madder: (bottom cover of the timing belt). Belt looks just fine, but until I get the bolt out obviously I can't start up the engine. :madder: :madder:

Just spent 2 hours removing parts from the engine. I can see the bolt - inside the lower timing belt cover between the belt and the pulley. Sure are allot of stuff to take off to get anywhere near it!

 

[Steve]

I believe (but don't quote me) that if an O2 sensor fails it will cause the engine to run lean, but surely the "check engine" light would have gone on?

One of the techs that frequent the boards will probably check in before too long......

 

[DrEntropy]

Banjo will know fer sure, but I'd say if the O2 sensor was FUBAR the mix will default to fat. Going the other way would burn a piston if ignored, they learned this lesson early and changed things.

If you're getting detonation there's more likely a timing issue.

As for that bolt, a magnet on a long stalk can be of use if you can see the beast.

 

[mikespain]

Hi-had one the other day ,exact same problem,chap had an overheating problem,so replaced the thermostat,all well for short while then started overheating again,after a chemical test of the gases in the coolant we found it to be a blown head gasket. I would get it tested for headgasket problems.The O2 sensor would throw a checklight

 

[70herald]

If you're getting detonation there's more likely a timing issue.

Ok, since the timing is electronic maybe a sensor? I guess that I might be about to drag it off to the stealership.
There is no way to adjust timing that I can see. timing the spark is all electronic.

As for that bolt, a magnet on a long stalk can be of use if you can see the beast.

Tried but there is a little aluminum protective ring down there with it. Oh well I guess that this is an excuse to replace the timing belt, would need to do it in the next year any way.

exact same problem,chap had an overheating problem,so replaced the thermostat,all well for short while then started overheating again,after a chemical test of the gases in the coolant we found it to be a blown head gasket. I would get it tested for headgasket problems.The O2 sensor would throw a checklight

Hope not! I should not that while it was running warm, it only went into the red zone for about a minute and that was at idle (and totally my fault) while driving, it got got warmer than normal, but not into the red zone.

 

[70herald]

I got the missing bolt out.
Now it looks like Mike is correct, there are bubbles in my coolant, so looks like the head is coming off soon.

I also hooked up my timing light. Timing seems to be dead on at up to 3000 rpm, but then on cyl 1 the light just went dead. On the other cylinders I got other less than stable readings. Could a failing gasket be causing the plugs to foul up? Burning the gas in the exhaust could explain the noise.

Kind of ticked off here.

 

[mikespain]

Hi again-If the plug is not firing,you should notice a definite misfire,pull the plug and have a look if its wet,and the coloration of the electrode.try swapping it with another plug,if the problem changes location with the plug then it is the plug.If not then try changing the plug lead location -same thing if prob changes with the lead -lead bad,if not it could be caused by head gasket.Try a compression check while messing with the plugs. sometimes the inductive clamp of the timing light does not pick the pulse up and the plug could be working fine.If after testing you deduce it is the headgasket,don't forget to have the head crack tested and refaced,quite a nice engine to work on.

 

[70herald]

Hi Mike
I brought it over to my local shop this morning, they leak tested the engine and said it was fine, but the distributor apparently needs replacement.
They have also pulled the radiator and are sending it to the radiator shop to be cleaned and tested.

 

[mikespain]

When you say they leak tested it ,did they do a test for gases in the cooling system or a pressure leak test,as the latter does not always show a head gasket leak.If the test for gases has not been done (cheap enough) i would do it before you do the rad,could save you doing the rad needlessly.If they have done the gases test then good- the rad is a cheaper job.With the bubbles coming up the radiator, you might get one now and again but they shouldn't be continuous Why was it your fault it went into the red? what did you do?-so difficult to diagnose things at a distance.

 

[70herald]

As far as I know they only did a pressure test. I will have to find out where to get the coolant tested for gases, the state of mechanics in this country can be a bit primitive at times.

They didn't replace the rad, they just boiled it out or however they cleaned it. It did have some accumulated crud in it so one way or the other, it needed some cleaning.

As for going into the red it was my fault. When I replaced the thermostat, I apparently didn't push the plug on to the sensor all the way so it worked its way back off. Fortunately, my wife almost always uses the A/C so the fan comes on anyway.

 

[mikespain]

Hi there -the stuff we use is a blue liquid,put into a special receptical on top of the radiator ,it turns yellow if there are any traces of gases from the cylinder

 

[70herald]

I will head off to a parts store and try to buy some.

 

[mikespain]

before you go into the expense of a new distributor fit the rad back and see what happens?has the car actually got a misfire'

 

[70herald]

Just got the car back. They put in a rebuilt distributor, had the radiator cleaned out (the top tank was taken off) and a new radiator cap. Total bill $388.

First of all, the engine seems smoother at idle, and it didn't miss/ping or whatever caused the noise last week.

Then I took it out on the highway and tried to get it to heat up. I went up and down a mountain at full throttle. The temp gauge was nice and stable.

My guess is that they may have been two separate problems.

and.....

Mike, thank you for your help!

 

[Banjo]

The older 4 cylinder Toyota engines were known for distributor issues. the dizzy lays horizontal, off the end of the camshaft, and over time the shaft seals start to leak, and then the oil contaminates the inside of the cap, as well as break down the coil which is also inside the cap. they start arcing in there and do all kinds of bad things. Often you will see one that will run fine for a few miles, then quit. then start up again after things cool off.
Glad you're back on the road.