Tag: Toyota

Testing an engine knock sensor with multimeter and a hammer

No, I am not suggesting to hammer the knock sensor ;).

Recently I was diagnosing a very intermittent error code 52 (knock sensor open/closed circuit) on a 4AFE powered Toyota Corolla.
I needed a way to test the actual functionality of the knock sensor in a garage.

From my understanding a typical knock sensor is pretty much a condenser microphone. So measuring resistance of it pretty much meaningless beyond finding a completely stuffed one. The repair manual suggest that the resistance of one should be above 1 MOhm, as it should be, as it is a capacitor.

One requirement for this kind of crude testing is having a multimeter that does capacitance testing in the nF range.

The particular knock sensor I was testing measured at about 6-7nF (temperature dependant) sensor alone, or ~7.5nF with the wiring.

The test is very simple, I have unplugged the sensor from the ECU, plugged one probe form the multimeter (set to Capacitance range) to the pin for the knock sensor on the ECU plug, and another on chassis/earth/ground. Then I knocked on a random bolt on the engine block and watch the measurment:

This resulted an increase of the capacitance for each knock (to over 8nF).

Another test that is not on the video, is basically using rattle gun on a bolt. This produced over 1.5nF increase.

I have also tested the sensor outside in a vice while heating it up with heat gun to 120 degrees C. The capacitance increased by ~2nF during heating. The sensor responding in similar way as above to light knocks on the vice anvil.

Alternative and more sophisticated way of testing is hooking up sensor to the microphone input on a cellphone/Laptop/PC but that would involve butchering a 3.5mm jack.

Replacing timing chain tensioner on a 1NZFE

Since day one of our ownership of this particular 1NZFE powered Toyota IST the engine was a bit on louder side.
Previously all my other cars had timing belts and I put it down to simply being a “feature” of chain.
After more family and friends upgraded their cars to xNZFE, it was clear that this engine was slightly louder in chain department then the rest (especially in the mornings).

One day after coming back from a holiday I started the car only to be greeted by loud chain slapping noise.

OMG! My wife’s car turned into a Nissan!

I decided to exorcise the Nissan out of it by replacing the chain tensioner and guides.

Below is how I did it, not necessary the “correct” way. This process took about 6 hours, good chunk of it was spent on cleaning the surfaces.
It was pretty much like replacing timing belt, except with way more RTV.
Over all I replaced two oil pump O-rings, front crank seal, valve cover gasket, both chain guides and chain tensioner.

In retrospect I prefer timing belts as opposed to timing chains, especially considering that the tensioners still fail on chains occasionally.

Interesting notes:

  • Old guides were PA66, new guides are PA46 (improved)
  • Old tensioner had larger oil hole than the new tensioner.
  • In hand old tensioner functioned correctly, but while fitted it would skip.
  • For some reason Toyota decided it is great idea to incorporate water pump flange into front cover. This creates a potential of RTV failure and leakage of coolant into sump. It also requires pump removal when removing front cover. It would saved me 2 hours if the pump was not part of the front cover.
  • The oil pump is mounted on front cover, thus requiring two O-rings for inlet and outlet.
  • One of those O-ring was completely flat, possibly leaking oil. It is hard to tell if the O-rings seated properly when fitting the cover.
  • For the crank pulley Toyota gone away from woodruff key in favour of tiny hollow pin.
  • The 10mm cover bolts and water pump bolts torqued at 11Nm. The 12mm cover nut and bolts torqued at 24Nm. The crank pulley went in hella-tight with crappy rattle gun and on top with some hammer on spanner action (It should be 128Nm). The tensioner and guides bolts are torqued to 9Nm.
  • I used Threebond grey RTV. The manual specified two kinds of RTVs for water pump and the rest of the cover, good luck buying two Toyota genuine RTV tubes ;).

Slack Before and After:

Continue reading Replacing timing chain tensioner on a 1NZFE

Toyota Vitz RS and its disappointing throttle response

Recently we got a nice 2005 Toyota Vitz RS (NCP91) with a manual transmission.

It is great car in all aspects except power delivery and throttle response is pathetic.

We already have 1NZ-FE powered car in the family – Toyota IST and unlike the Vitz RS it is not that pathetic (in fact it is kind of fun to drive).
Yes, I have driven multiple Vitz RS and they were all asthmatic.
So what is so different between IST and RS? IST happens to have cable driven throttle, while RS has drive-by-wire.

Here is where Toyota screwed up and completely ruined the car: they made throttle map to emulate steam roller.

If I was Toyota I would not stick RS badge on the car, it is not a hot hatch simply because it lacks in engine department. Vitz RS should have came out with 1ZZFE at least.
What is even worse they decided to stick this anaemic throttle map on top. As if the car was not boring enough.

After consulting google and various forums I had two minor mod options:

1) Stick a throttle controller
2) Stick a throttle body off 1ZZFE.

I decided to go for second option as it is transparent from end user point of view. There are a few minor hurdles with this mod.

Continue reading Toyota Vitz RS and its disappointing throttle response

Subaru Genuine Parts in New Zealand

I have owned numerous Toyotas in past.
When switching from Toyota to Subaru I did not expect to be shocked by such price difference of genuine parts between each brand.
Both Japanese, both of good quality vehicles, similar niche…

Oil and air filters are priced very close (about ~$20NZD for oil filter and ~$40NZD for air filter), beyond that Subaru parts are rip-off.

For example, for my 1998 ST205 Celica GT4, the genuine front brake rotors were ~130NZD each. About double of aftermarket from BNT or Partmaster.
Considering brake rotors are consumables that is very reasonable price.
When I inquired about rotors for my 2008 GRB Subaru WRX STI (JDM), initially I was quoted ~1060NZ each (retail), that came down to $900NZ each. After shopping around I found the cheapest price in New Zealand for genuine front rotor would be ~$695NZ each (trade price BTW).

What is the difference between Toyota Celica GT4 and Subaru WRX STI rotors:
dimensionally they are very close:
315mm x 32mm
vs
326mm x 30mm
So please explain to me why such a price difference?
Genuine Brembo rotors can be bought in USA for about $160USD retail (it would cost uneconomical amount of $$$ to get them shipped to NZ).

Another example is another consumable, brake pads, Toyota Genuine front pads for ST205 Celica (very similar to STI pads) cost about ~$90NZD.
Subaru, at first I was quoted ~$730NZD, then I got “trade” price of ~$620NZD (from Winger). In USA same pads cost around $200USD ($260NZ).

So given the options I got rotors from Partmaster (“Italian made”) for $90NZD each, and pads (Bendix SRT) from BNT for $280NZD a set. Bendix SRT pads were later replaced by Ferodo DS2500 all round (a bit better pad in my opinion).

When I imported my STI it had rear cargo blind missing (BTW Subaru calls it “TONNEAU COVER”, Part number 65550FG002ML).
I enquired about it locally, Winger quoted me ~$430NZD and that was “trade” price (fuck that differentiation). The retail was about $630NZD. For piece of vinyl on a stick with a spring, FFS!?!?
Same part in USA costs around $140USD ($180NZD).
In Japan I got price of 22000JPY, which works out to $235NZD (I don’t have to pay shipping due to special arrangements).
So how does $250 (retail) item becomes $630 item, by just arriving to NZ?

I don’t even dare to think about how much Subaru will charge me for wear items like shocks (Toyota price is ~$140NZD each) and bushes…

Hopefully due to Toyota’s stake in Subaru will have some culture changes, which will lead to price standardisation, making consumables cost like consumables (and not gold-pressed latinum). One would only hope.