My Fix-it thread.

[Conan]

Why "my" thread? Because I'm dinking around with stuff so much that I just thought it would be easier to have my own thread.

I'm still trying to ascertain what is causing the ticking sound in the cam area. Question: Should the rollers/rockers maintain contact with the cam lobes at all times? I think I noticed one (or more) of the intake cam rollers was NOT in contact with the lobe all the way around while I manually rotated the engine. It was one of the rollers for the bigger lobe.

Also, what are these?

[turbophil]

First circle is the coolant drain for the block. Uber handy when removing the engine.

2nd Circle is the capped off air injection pipe for Toyota emission systems that we don't have and further evidence of Lotus cost cutting by not designing their own manifold bespoke to the Lotus

Best,

Phil

[Conan]

Originally Posted by turbophil

First circle is the coolant drain for the block. Uber handy when removing the engine.

2nd Circle is the capped off air injection pipe for Toyota emission systems that we don't have and further evidence of Lotus cost cutting by not designing their own manifold bespoke to the Lotus

Best,

Phil

Thanks, Phil. Do you happen to know the answer to the first question?

[fpitas]

There is a small clearance, usually called valve lash. See about 2/3 of the way down this page for typical values:

Toyota* Engine Information

[Conan]

After multiple visual inspections, I still don't see anything. Yet the ticking noise persists. I don't have a lot of hands-on experience with engines, but I know enough to realize that something must be wrong. I'll most likely need to pull the whole head because at this point I'm wondering if I have a bent valve or something. I really don't know. Without seeing the pieces individually (rollers, springs, valves, etc) I can't see what else it might be.

Like I said before, this would be the first time I've ever taken anything apart on a motor -- internals, anyway. I've installed complete brake systems, replaced clutches/flywheels, installed a complete suspension, exhaust, etc, but never engines. OK, I did do the rod bearings on a 944, but someone held my hand the whole way and that didn't involve taking apart any of the real plumbing -- just drop the front suspension member and the oil pan and you're there.

If I end up doing this, can anyone give me a list of tools I would need? I've got all the basic stuff, but what about feeler gauges, micrometers, flux capacitors, etc? And are there any tips someone could offer?

Thanks.

[MaineLotus]

Some ticking is normal. Have you listened to other 2zz's to determine if yours is different. Removing the head while the engine is in the car isn't impossible, but it does involve some work. You have to also remove the timing chain cover and that involves removing the pulleys and access is tight.

Removing the head also means the cams and chain are removed. Reassembly involves finding TDC and setting the timing chain correctly. Done incorrectly and you will certainly have bent valves afterwards - it is an interference design. I did it and consider myself of average intelligence.

Most important tool is the Toyota service manual. Good luck!

[glb]

Wouldn't it be worth running a compression test or, better, leakdown test before taking anything apart?

[tesprit]

Originally Posted by glb

Wouldn't it be worth running a compression test or, better, leakdown test before taking anything apart?

+1
Before you start tearing down the engine, you should determine what is wrong and if disassembly is required. In addition to compression and leakdown tests, why not measure the valve clearances first. If you have a sticky or bent valve, it will have a very large clearance compared to the rest and will be easy to find.

[Conan]

Originally Posted by MaineLotus

Some ticking is normal. Have you listened to other 2zz's to determine if yours is different. Removing the head while the engine is in the car isn't impossible, but it does involve some work. You have to also remove the timing chain cover and that involves removing the pulleys and access is tight.

Removing the head also means the cams and chain are removed. Reassembly involves finding TDC and setting the timing chain correctly. Done incorrectly and you will certainly have bent valves afterwards - it is an interference design. I did it and consider myself of average intelligence.

Most important tool is the Toyota service manual. Good luck!

Thanks. I guess I'm focusing on the fact that it did't used to make the sound. It started 4 months ago. And it seems unusually loud. I've been around several other Elise/Exige at the track and don't remember hearing anything like this.

Glb, probably a good idea. How do you do one?

[Conan]

Originally Posted by tesprit

+1
Before you start tearing down the engine, you should determine what is wrong and if disassembly is required. In addition to compression and leakdown tests, why not measure the valve clearances first. If you have a sticky or bent valve, it will have a very large clearance compared to the rest and will be easy to find.

Thanks, but like I said, I don't have any experience. That's probably a simple thing if you know how, but I don't. However, I want to!

[waydui]

Originally Posted by MaineLotus

Some ticking is normal. Have you listened to other 2zz's to determine if yours is different.

FWIW, my car ('05 Elise) has a ticking sound. Aways had it. It's a regular ticking. I don't have any cam lobe issues either.

I believe that the ticking is the fuel injectors (solenoids actuating on/off) and not anything to do with the valvetrain.

Regards,
Wayne

[MaineLotus]

Originally Posted by Conan

Thanks, but like I said, I don't have any experience. That's probably a simple thing if you know how, but I don't. However, I want to!

The Toyota service manual describes how to measure valve clearance. All you need is a set of feeler gauges and a few standard tools.

[glb]

Originally Posted by Conan

Glb, probably a good idea. How do you do one?

Compression test is easier. W/engine at operating temp but stopped, keep throttle open (so air can get in).

Unscrew spk plug #1. Screw in compression tester. Crank engine and record reading. Rinse, repeat for 3 more cylinders.

You should see no more than a slight (<10% variation). A large variation could then be:

Bent valve (not likely)
Worn rings (ditto)

Pour a bit of oil in suspect cylinder, retest now that the oil sealed the rings some. if compression comes up, it's a ring issue. If not up, it's a valve or other issue.

There is a more detailed thread on this test here somewhere.


Leakdown test: more difficult (but not much) and more meaningful:

Basically, it involves filling the cylinder w/compressed air via a screwed in fitting. Checking how long it takes for air pressure in cyl to drop, but I can't remember the normal vs abnormal comparison at moment.

Cyl must have both valves closed, ie. TDC Top dead center. (You can pull cam cover off to see, or feel compression stroke.)

One can hear where air is escaping if there's enough of it. If you hear it thru dipstick tube: rings. Exhaust: valve, etc. Intake: valve. Tire: you have completely screwed up the directions.

A compression tester is cheap and useful. Start w/that.

[tesprit]

Originally Posted by Conan

Thanks, but like I said, I don't have any experience. That's probably a simple thing if you know how, but I don't. However, I want to!

It is fairly simple to check the valve clearances. You will need to remove the valve cover and remove the passenger side rear wheel and fender liner to gain access to the crankshaft pulley nut so you can turn the crankshaft by hand with a wrench. Now it is just a matter of turning the crankshaft until the valves on the cylinder you want to check are closed. You can either turn the crankshaft until the piston in the cylinder you want to check is on top dead center (TDC) of its compression stroke (all the valves are closed) or just check each valve that has the heel of the camshaft lobe on the lifter (valve is closed in this position) and then turn the crankshaft some more until the next valve is closed to check the clearance and so on. You check the clearance with a feeler gauge which is just a bunch of different thickness strips of metal to insert into the clearance space and they are cheap and available at any auto parts store. If you read through the Toyota engine manual it describes exactly how to use the feeler gauge and what the clearances should measure. Also remember not to try checking the clearances on the valves actuated by the VVT system (large lobes on the intake cam) as the contact pads of the cam followers are lightly spring loaded to keep them in contact with the cam lobes at all times so the valve clearance on these valves is zero. If upon checking the clearances, you find an excessive amount of clearance (wide clearance gap) on a valve, that would be your suspect for causing the loud tapping noise. You can then follow up with a compression check on that cylinder as described in the post above to determine if you have a leaking/bent/sticky valve.

[Conan]

You guys rock!!

[Conan]

I recently had a more experienced ear come over and give an opinion. He didn't feel it was anything serious and was most likely a noisy injector. Anyone with an opinion on the likelihood of that?

In the meantime, I found a welder for my exhaust and will be taking it there Monday. I think the right-hand hanger design on the exhaust (Larini 8") is weak as there isn't any triangulation so you get a lot of flexing right at the weld point.

I also (FINALLY) put the adjustable suspension on. Pretty easy, really, although finding a good spot for the reservoirs up front was tricky.

Once the car is back together (hopefully sometime next week) I'll get it corner balanced.

[Conan]

Man I missed this car. Got it back together again today and took my very excited son for a ride. The new suspension is fun. I'll definitely have to get it corner balanced, but it's still better than before, that's for sure.

And for whatever reason, no ticking sound. I'm sure it will be back, though.

But in the meantime, GOD I LOVE THIS CAR. 2 months away was too much.