4AGZE Blowing Noise

[SuperRedMR2]

I just did another compression test with a stone cold engine and 1, 3 & 4 are putting out 130 and 2 is at 180 - I did pour some oil into it yesterday though but I would have thought that would have drained away in 18 hours? and not made a difference?

[SuperRedMR2]

What is the standard compression numbers for a GZE engine? I've read somewhere that's it's between 156 to 121 psi...

[SuperRedMR2]

Seems i've been doing the test wrong.

Not had the throttle fully open either. I'll test again today.

[SuperRedMR2]

1= 145
2= 145
3= 150
4= 150

seems I have no issues but doesn't explain bogging noise.

[monkeymax]

Hi Alex,
As you thought, BGB states 156psi for 4AGZE, with minimum at 121psi and maximum difference at 14psi. Looks like yours is within limits:


Have you tried uploading the video to Dropbox, then getting a public link? If you've got the vid but can't upload it, PM me and I'll find somewhere to host it for you.

[SuperRedMR2]

I'll create a youtube account and do it that way. Thanks though Max

Been meaning to make an account so we can upload crazy videos of our three cats!

[SuperRedMR2]

Got the car into my garage tonight and comp tested again with hot engine and throttle open. 145 across the board.

However upon removal of the plugs I found two of my grade 7 iridium plugs were shattered. Can't understand how I missed that before unless it's happened since.

This would surely cause an issue with a spark and obv not show up on a comp test.

What would cause a plug to shatter?

[Lauren]

What would cause a plug to shatter?

Physical contact with something. What else can it be?

I tried to talk to you at JAE, but you had some kind of personal issue and went. Sorry I didn't catch up with you after that, you didn't seem to be about much.

Are these the cylinder(s) you dropped the screwdriver end in?

[monkeymax]

Could you be more specific about the plugs? How are they shattered? Physical contact in the cylinder would be awful and I'm wondering whether they were damaged before they went in somehow (or while going in) and the thermal shock (getting hot & cool in the run cycle) has just meant a small crack has become a catastrophic crack and they've broken apart. That'd leave bits inside the cylinder though which would obviously be quite bad!

[SuperRedMR2]

The insulation at the top of the plug (2-off) have shattered and bits have come away.

They didn't fall down the hole though. I'm sure they were not like that when I first took them out a few weeks ago, but maybe I just didn't notice and was far more concerned compression testing it.

[SuperRedMR2]

What would cause a plug to shatter?

Physical contact with something. What else can it be?

I tried to talk to you at JAE, but you had some kind of personal issue and went. Sorry I didn't catch up with you after that, you didn't seem to be about much.

Are these the cylinder(s) you dropped the screwdriver end in?

The cylinder the screwdriver end fell in, did damage the end of the plug (in the head) as it closed up the distance between the centre electrode and the ground electrode, basically there was no gap like something had hit it.

Strangely though, this wasn't either one of the plugs that had shattered.

I did get all of the screwdriver out however with a makeshift magnet.

I was wondering like Max said, if there is any thermal issues that could cause it to shatter?

[monkeymax]

If they were dropped, I think that could possibly cause what you're seeing. Even under heavy load, a good condition spark plug shouldn't do that, so something has happened to cause the shattering. Though having never seen this before, I'm speculating (though speculating based on some experience of producing sintered ceramics and treatments of them, which I believe is what is used for the insulator part on spark plugs). Not sure the shattered points should cause problems, but is the inner core visible through the insulator? If so, it may be grounding on the head reducing the spark power?

Do you have another set of spark plugs to test - even the old ones? (I was assuming these are new, but actually that one looks quite used) Are you sure you tightened the spark plugs sufficiently? (sorry, I know that last bit is a stupid question but it would explain the noise you are hearing if some pressure is being lost around the plug, and I'm just thinking out loud on causes) How do the threads look on the plugs?

Another stupid question perhaps, but are you sure there are no spark plug/screwdriver bits in the cylinder? I think it's still head off time, unfortunately.

[SuperRedMR2]

I've been in Teesside for work for the last few days so I will get back to the car when I get home this evening.

Does anyone know if I can simply take the alternator belt off and pivot the alternator downward, as this is blocking access to one of the exhaust manifold bolts...

I'm going to buy a set of standard plugs tomorrow. I know i'm going to have to take the head off eventually Max as I'm going to rebuild it anyway.

[SuperRedMR2]

I have thought of something crazy though...

I could look into a 7agze...

[SuperRedMR2]

How do I get the alternator belt off?

[jimi]

I.M.O
That looks like the plug socket has been at an angle / not fully on the hex and has put stress on the insulator causing it to crack.

[SuperRedMR2]

Had the car running last night.

Was too late to get it up to temperature because of my neighbours.

It sounded fine other than the rod knock I have at start up.

I replaced the two broken plugs with two standard plugs and there was no missing. I also managed to pivot the alternator which enabled me to tighten a loose exhaust manifold bolt which could have contributed to the blowing.

However the plan is to rebuild it over October/November with a full bottom end strip. I have sourced a near perfect crankshaft so this will go in along with new Toyota (yes Toyota) bearings. I will also try and find the series 3 4AGZE pistons.

[mark35]

Try eBay I find genuine Toyota bearings parts from a place called partsouq.
13041-16071-02 £5.59 each
13041-16071-01 £5.59 each
11701-16010-03 £9.03 each

They were all genuine bearings sealed parts in boxes.

[SuperRedMR2]

Thanks Mark, but they appear to be based in the UAE.

Not keen on spending £13 on postage when Toyota is 4 miles away from me. Good spot though in case I cannot get them from my local.

[mark35]

You might change your mind when you find out how much they cost.
Think is was about £250 with the vat and that's with 10% off for being in the club. I ordered from them just before Christmas and I had them in 3 days. Did get stung for import tax but it still was a lot cheaper than buying in the uk.