Cuore L251 - Noisy Engine and Loss of Power

[bluedog]

To the valve clearence check and the needed gaskets:

Don't confuse cylinder head gasket and valve cover seal.

When checking/adjusting valve clearance, you do not remove the cylinder head, and therefore you don't need a cylinder head gasket. You don't even touch that.

You only remove the valve cover and if you need to replace shims, you take out the camshaft(s). Cylinder head still stays in place then.

People who must know that recommend, however, to replace the valve cover sealing with a new one. Otherwise, the Engine might spill oil trough the reused one.

But that brings me to an other good Idea, for finding the reason of the power loss.

Do a Compression test. That can show you, if all valves are undamaged (sealing off the combustion chamber properly) and if the cylinder head gasket is ok.

Complete loss of Compression on one Cylinder would indicate, there is a valve burnt up, or a leak in the cylinder head gasket. As long as all three cylinders have more or less the same pressure value, the valves and the Cylinder head gasket are ok, and you just have to take care of the valve clearence itself.

[terios]

Zitat von bluedog

Don't confuse cylinder head gasket and valve cover seal.
.

I didn't. May be just the term I used was not clear "head cylider cover seal"

let's just briefely summarize all the tests mentionned till now:

- Fuel octane booster
- Fuel pressure check
- Timing light test
- Engine scan
- New sparks (they are new from Daihatsu dealer, I'll try to send you the mode)
- Compression test
- Valve clarance inspection

Coming back later.

[bluedog]

I'd propose to do it in the following order:

- new spark plugs
- ignition timing test
- Engine control unit memory scan (read out error reports, if any present)
- check ignition coils
- compression test
- Fuel pressure check
- valve clearance inspection
- Octane booster

I come to that order by asking, what could cause engine noises.

For that it needs a bit more than bad fuel or low fuel pressure, so lets do that after we run out of more probable Ideas...

First, lets take care of the ignition. That takes the power out of the fuel. Then, see if the engine mechanically is ok. That means a compression test.

Give it a set of new spark plugs, just to make sure, ignition isn't the problem, and because you don't need any special tool. A 16mm plug spanner will do...

Then, if the problem still persists, check ignition timing. I think, that must be ok, because if not, you would not get >140km/h out of the Engine... it would maybe not even start. But, it is a test which doesn't take to much time and any mechanic should be able to do that.
If the engine Timing is wrong, there must be a problem with the timing belt or with the camshaft/crankshaft position sensor. You can't adjust ignition timing, so if it doesnt right, you know where to look for the reason...

If that is ok, go to the Daihatsu dealer and let him read out the ecu's memory. If there's errors reported, you get a hint where to look for the solution.

At this point, only the ignition coils rest from the ignition System.

If they are ok, lets think about fuel pressure. If the mixture is too lean, you have power loss, and if you have the pressure gauge and know what to do, it is about 30min. of work only, and you don't need to buy any gasket or other spare parts just for test.

So, either you look after the mechanical part (valve clearance, proper compression rate) but you'll need a pro for that, because you probably do not have the tools... It would mean some real work, anyway, whilst before, everything was quick and easy to check;

or you can try octane booster, now that you are sure the ignition must work.

If nothing helps, there is still the MAP sensor left...

[terios]

Sounds like a good plan, Thanks.

We have to wait till next week when I'm home back.

[terios]

Well, there is no much update to come up with till now...

Meanwhile, I just want to open a subsidary subject:

How much is the engine oil consumption on your cuores L251: xx L/1000km ? please to provide the oil used too.

knowing that between "Full" and "Empty" indications on the oil gauge, there is 0.8 L, I can say my engine is consuming about 0.2 L/1000 km. Using 5W40 full synthetic (API SM)

Is it normal?!

(EJ-VE or DE will not make difference here I assume)

[LSirion]

It´s normal. Maybe a little bit high for a EJ-Motor, but this is because of the higher rpm you drive. Less rpm, less oil consumption.

[terios]

It's not my car, I drive it very rarely. Besides this, in my mind oil consumption is more likely to happen in city driving with little rpms and to much stops and goes...

I'm not fully disposed to regulary inspect this car, that's why I'm not really sure of the 0.2l/1000km, sometimes it seems to be higher than that.

Is it normal to get a "low" level before you rich 5000km? the most tricky thing in all this, there is no smoke, neither leaks, neither oily air filter, where it goes then??!

[terios]

Just for info, I've met already two cuore's drivers and shared with me the same observation: at relatively high mileage > 150.000 km their cars consumes oil without smokes nor leaks!

[bluedog]

that is a known issue, due to very narrow oil drain holes inside the piston ring grooves.

When the oil becomes hot enough (right at the piston is approximately the hottest spot within the engine, which is reached by the engine oil), it tends to plug up those tiny but important drain holes.

Another possible cause for oil consumption are the valve seat rings. That would cause oil smoke after an idle-phase, when you turn up the engine. It's quite more probable, that its the first, above mentioned cause.

[25Plus]

My cuore (215000 km) has now an oil consumption of about 0,1 l/1000 km (perhaps higher). Until 180000 km the oil consumption was about 0,1-0,2 l/15000 km. But the whole drivetrain is getting louder with more and more vibrations when driven unter 2000 rpm.

I don´t know the problem but I think that the drivetrain is not built to reach much more than 200000 km. The gearbox also gets louder and the second gear synchronization is getting worse, also the clutch.

But since I like the car it will get a new drivetrain some day and only be my sunday- and good weather car ;-).