4AGZE Blowing Noise

[SuperRedMR2]

Hi,

I've got the blocked ABV mod on my charger conversion so with it on all the time it makes diagnosing a noise a bit of a problem.

However, I've just had my magnex back box welded up as there was a gaping hole where the hanger had snapped off along with a new flexi, my car or exhaust is still blowing like hell! Makes it sound almost like it's knocking.

There are no knocking noises at idle but in gear it sounds like it is, but I suspect this is the exhaust.

If I make it to JAE (fingers crossed) can someone stick their head in my engine bay and tell me if its rod bearings, supercharger bearings or a blowing manifold?

I intend on buying the charger oil at the weekend and changing this before JAE.

Also, I've upgraded to Paul Woods' poly engine mounts - if there is anything loose in the engine bay, would these amplify the noise maybe?

Cheers

[PW@Woodsport]

Post up a video of it running and maybe we can help diagnose it.

[SuperRedMR2]

I can say what it sounds like from past experience.

It sounds like it's running on three cylinders. But there is no power loss, no spluttering. Like I've got a wet plug / faulty HT Lead.

I even took off 2 HT leads with the engine running and it made no difference at all.

It goes away after 3K rpm. It feels fine, just doesn't sound right.

It doesn't knock under load like a bearing would and it doesn't knock at idle either.

Will post a video up later.

[PW@Woodsport]

I even took off 2 HT leads with the engine running and it made no difference at all.

If you did that then the engine must only be running on two cylinders!

Removing any HT lead should instantly change the way the engine sounds/runs.

[SuperRedMR2]

Hi Paul,

Didn't sound like it was at all. It didn't start with both leads off though lol.

Must be something to do with the charger?

[Lauren]

It's hard to tell from your description. Happy to have a look at JAE.

Posting the video up may well help.

[SuperRedMR2]

I cannot seem to upload a video to photobucket

Can I email it to anyone?

[Lauren]

Youtube?

Pretty sure Photobucket is over nowadays.

[SuperRedMR2]

Not sure it matters.

Did a compression check with hot engine.

1,3 & 4 are 145 psi, 2 is at 105.

[oukie]

Oh dear.

[SuperRedMR2]

Won't be going Jae in it unless I can find out the issue. Hoping it's a stuck valve.

But there is no performance issues at all.

How hard is it to get the head off with the charger in place?

I'm going to take the cam covers off first to check if there are any extra large gaps in valve clearances.

What do ppl think?

[Lauren]

Did you rebuild this engine? Looks like time for another rebuild.

The supercharger is not anywhere near the head, so that won't cause you an issue.

[PW@Woodsport]

#2 is too low, probably a leaking valve or ringland issue, perhaps even HG.

I'm going to take the cam covers off first to check if there are any extra large gaps in valve clearances

If you think about it larger valve clearances won't lower the CR at all, it would need to be an extra tight clearance holding a valve slightly open, which I highly doubt, it would need to have been rebuilt by a chimp to have overly tight valve clearances.

I suggest carrying out a leakdown test to further confirm #2 has a mechanical issue.

[kaiowas]

The supercharger is not anywhere near the head, so that won't cause you an issue.

The top mounts for the SC attach to the inlet manifold and the SC itself blocks access to some of the manifold bolts so it is a factor. I have removed an SC head in situ bit I remember it being a bit fiddly. I'm pretty sure I left the inlet manifold attached to the head and brought it out in one piece.

[SuperRedMR2]

The supercharger is not anywhere near the head, so that won't cause you an issue.

The top mounts for the SC attach to the inlet manifold and the SC itself blocks access to some of the manifold bolts so it is a factor. I have removed an SC head in situ bit I remember it being a bit fiddly. I'm pretty sure I left the inlet manifold attached to the head and brought it out in one piece.

I was hoping I could bring it out in one piece. That'll make it easier (ish), except it'll be heavy. If it can come out in one piece I won't have to faff around with the vac pipes and remembering where they all go.

[SuperRedMR2]

Did you rebuild this engine? Looks like time for another rebuild.

The supercharger is not anywhere near the head, so that won't cause you an issue.

We changed the head gasket as a precaution.

The old gasket that came off left some residue which we removed from the block face. The new gasket went onto a flat surface.

I was going to rebuild it after JAE anyway, just wasn't expect to not have it for JAE seriously gutted, however this is a 4AGZE and there will be other times to take it places. Need to get it back to it's best.

The camshafts and rest of head looked okay so we left it as is.

[SuperRedMR2]

#2 is too low, probably a leaking valve or ringland issue, perhaps even HG.

I'm going to take the cam covers off first to check if there are any extra large gaps in valve clearances

If you think about it larger valve clearances won't lower the CR at all, it would need to be an extra tight clearance holding a valve slightly open, which I highly doubt, it would need to have been rebuilt by a chimp to have overly tight valve clearances.

I suggest carrying out a leakdown test to further confirm #2 has a mechanical issue.

Hi Paul,

Unfortunately I have no access to any comp air to test this theory. I'll still whip the cam covers off later - would it be dreadfully obvious in the valve train if there is an issue?

[SuperRedMR2]

What I do not understand is; why did I not notice any difference in power? I even gave it a good test yesterday on the way home and acceleration was not affected!

It is not using any oil, putting out blue or white smoke. No exhaust smell in the coolant, no bubbling coolant, nothing.

I was looking at the 4AGZE series 3 8:9 pistons for when I rebuilt this, so with the head having to come off this tempt me further.

[kaiowas]

I was hoping I could bring it out in one piece. That'll make it easier (ish), except it'll be heavy. If it can come out in one piece I won't have to faff around with the vac pipes and remembering where they all go.

My memory is slowly returning...

I seem to recall that if you undo the two upper mountings for the SC and also remove the studs that go through the SC and into the manifold then the head/manifold can come off together leaving the SC in place. Getting access to disconnect the metal water pipes that run under the manifold is tricky but doable.

[oukie]

We changed the head gasket as a precaution.

Alex, this is where you possibly went wrong, unless I had suspected hg failure, I'd of just dropped the engine in and ran/tested it as it was an unknown.
You may have caused the issue by taking it apart, if I changed a head gasket I don't think I'd do it without having it tested to see if it was true.