reyanth

Hi! So as the title sais I'm having issues with ma doch mugen's (EP3 Type r 2002 K20A2) VTEC. Engine has 235k km (135k miles..ish) on the clock.

As far as I know there are only few mods on the car in case you need to know:
- Freelow air filter
- Custom exhaust with cat, OEM manifold

Issue:
Around 6000rpm when the VTEC is suppose to engage the engine makes a grind noice and hesitates BEFORE the vtec actually kicks in.
- The ginding noice is worse depending on throttle input. More throttle -> Perhaps more longer grind before vtec engages.
- If you cruise over the 6000rpm area with gentle throttle, there is no grind noice and vtec works.
- If you shift down so the rpm jumps over 6000rpm, there is no noice and vtec works.
- When accelerating and engine making noice around 6k, if you lift throttle a bit it makes the noice go away faster and vtec strikes back!

Current:
- New engine oil and filter (oil level check ok!)
- Engine running temp around 88-90c (180-195f)
- Idle rpm around 900 and smooth
- Battery voltage on 12.6v-ish, when charging around 14v-ish.
- No leaks, does not burn oil nor water.
- Throttle a bit hesitant on low % throttle acceleration. 0.5-1sec "lag/hesitation" before engine starts to pull.
- No warning lights on dash
- No fault codes

Not sure what else to say, but I'd really want this vtec gremlin sorted out! Thanks!

thisguyaves

Firstly, there is an EP3 specific section in the forums, might have better luck there.

What's your oil pressure at? I'd start by removing your VTC solenoid (1x10mm bolt) and vtec solenoid (3x10mm bolt) and checking the screens for blockages. Any check engine lights? Your hesitant throttle makes me think you might have a VTC related issue.

reyanth

Not sure of oil preausre cause don't have a cauge. No warning lights on and no fault codes. Added this post to the EP3 section also, thanks!

Going to check the solenoids asap.

reyanth

Did a check on the VTC and VTEC solenoids. No oil clogs or visible problems.

thisguyaves

Any recent oil changes showing sludge in the oil? how about under the valve cover, any particulates on or around the rockers? Also with the valve cover off, verify the intake gear is locked to the intake cam (VTC is off, cam should be in locked position)

reyanth

Just had one oil change so far (haven't had the car for long) and the only thing I noticed was the oil being runny and black. No sludge nor suspicious metal..thingies..

Going to check under valve cover next..

reyanth

I had a moment of tought and came up with the theory, could the vtec issue be timing belt related? A worn/streched timing belt could result in timing missplace and therefore mess up the engage of vtec?

In theory, when you boot throttle down the tension in the belt would result in more timing missplace as it streches the chain VS not booting the trottle too much or easing a bit of it would not put as much tension to the chain?

thisguyaves

Well, timing *chain*, but it could be. You'd probably get misfire or camshaft position errors though...

reyanth

Yeah chain, brainfart there.. And true, it should give out other issues like so.

thisguyaves

I'm going to keep it chalked up to a oil pressure issue somewhere, might be a good excuse to get a gauge.