P2646 — 2004 Honda Civic L4-1.7L SOHC Service Manual | Operation CHARM

Repair and Diagnosis — 2004 Honda Civic L4-1.7L SOHC Service Manual | Operation CHARM

A L L Diagnostic Trouble Codes ( DTC ) — 2004 Honda Civic L4-1.7L SOHC Service Manual | Operation CHARM

 

Thanks for the links. I'm picking up the car tonight as dealer was basically useless. Going to check my wiring and see if any connections broke.

 

dealerships are fucking useless these days due to having to find a profit somewhere, and that usually ends up in hiring green thumbs that can be trained, rather than veteran mechanics who have been around the block


insufficient oil pressure absolutely needs PROPER diagnostics, not parts thrown at it.


Go to harbor frieght and grab an engien oil pressure test kit, install the fittings in place of the oil switch, and verify you are getting oil pressure. It is as simple as that, to see if teh engien is happy or not.


If it makes good pressure, cut the BS and just re-wire the vtec solenoid directly to the ecu. THse are old cars, and the harness's are brittle, prone to getting rubbed the wrong way, and just in general taking a shit.

Father Time whips everyone!

On my own d17 vtec engines, I have definitely found burrs in the pins, combined with weak oil pressure, from a simple bad oring in teh oil pump. Just toss a new pump into it along with a timing belt and water pump.

Seems you have had the car quite a long time, it is way overdue if it has not been done since 2017

 

The dealer decided not to charge me for that diagnostic due to the fact they couldn't tell me anything other than I had oil pressure. Not sure if it was the correct psi though. I'm going to buy the oil pressure test kit and test for proper psi. Going to test my wiring as well as I repinned the connector during the swap. Perhaps one of my wires crapped out.

I had to swap engines three weeks after I bought the car as it ate up the timing belt in the driveway. It was a cheap auto zone one. I replaced the timing belt, tensioner and water pump with factory honda parts when I installed the jdm.

Interesting about the o ring in the oil pump. I had a quad ring go bad on a 5.7LS engine oil pump pick up tube that gave intermittent valve clatter and low oil pressure. $20.00 fix.
How bad is it to replace an oil pump on a D series?

 

Laughs in 5.7LS leaks.....

 

Welcome! Please document what you find as you go along - there needs to be MORE d17 content, even though they are the bastard children of the d-series.
I've noticed on social media that they are getting more and more attention, as they are still relatively cheap.

 

the oil pump on the D is easy adn straight forward, but you will have the timing stuff off anyways for access.

DO yourself a favor, grab a timing kit, honda OEM timing spring from a dealership (not online, too many fake parts). for timing, rockauto has good ones.

The new oil pump will include the O ring and mounting face gasket.

If it makes good pressure, shouldnt need to do it, but I would still recommend these things after 8 years.


I dont really care how long people in the past have gone on these parts, parts today are NOT the same quality, and they started going bad as early as 2010, while recovering from the economy shit.



Fun fact on the D17's you can use d15/d16 intake and exhaust manifolds! You will need a crafty bolt on clamp setup for exhaust, but intake just needs some drilling. If you keep the EGR/injector plate, you make it easier.

Im actually going to be putting a d17 exhaust manifold on my d16y7 99 car, so I can enjoy some cheap 4-1 header action. D15/d16 headers that actually help are near impossible, and factory 99-00 EX manifolds are gold, according to ebay sellers

 

The timing belt, tensioner and water pump are honda parts and have 35k on them so hoping I won't have to replace unless oil pump is bad, then I might as well. Can't do the test until next week but I will document it all Here.

Will check the wiring, I ran the wires for solenoid and pressure switch when the EX computer went in. Ripinned the ecm connector and soldered on pigtails I got from the boneyard. They shouldn't be brittle but I'm not going to say they didn't fail.

When the ecm commands and the solenoid opens, how does the oil get to the locking pistons in the rockers? Is there an oil galley? It looked to me oil from the solenoid flows into the head and hits a ramp then up to the rocker arm shaft. Just trying to get a better idea how the rockers lock.

This D17 has been a great engine up until this point. Rolling down the freeway at 80mph and still getting 38mpg. Only other issues I have is passenger window stops an inch or so from going all the way down and the key fob won't lock or unlock the doors. These issues started way before the vtec issue.

 

the rockers lock via oil pressure shoving pins sideways into the rocker arms when the vtec solenoid engages and allows engine oil pressure to apply more force.

Ever driven a vtec engine along a long high speed corner and lost a ton of power for a few seconds?

The system is designed in such a way that if you lose oil pressure, vtec disengages whether the ecu wants vtec or not.

There is actually a small plug on teh side of the head you can apply oil or air pressure to, to manually engage vtec to test, and this also allows you to verify valve lash is properly adjusted under vtec engagement.



I find it more worthwhile to buy a spare head and compeltely go over it. Have valve guides replaced, valve seats checked out, valves themselves measured, etc.... Then chuck it on, torque the ehad down, do valve lash, drive 3-500 miles, re-torque the head, and enjoy another decade+ of reliable fun

 

Ok, finally am able to work on my pile today.
I verified my connections to the ECM are good. Did an oil test and have over 80 PSI when I applied power to VTEC solenoid. During the test I can hear an intermittent knock from the cylinder head. It is not coming from the bottom end. Going to pull the valve cover and get eyes on the valve train as I believe it to be the source of my knock.

Anything in particular I should be looking at? It sounds like something is loose somewhere in the valve train.

Nothing jumps out at me as being an issue. Can I pull the 11 bolts holding the valve train on and inspect on the bench?

 

remove valvecover and clean what you can.

oil orifice plug

Camshaft, Rocker Arm, Camshaft Seal and Pulley Installation — 2002 Honda Civic EX Coupe L4-1668cc 1.7L SOHC (VTEC) MFI Service Manual | Operation CHARM

Detailed repair manual for the 2002 Honda Civic EX Coupe L4-1668cc 1.7L SOHC (VTEC) MFI.

charm.li

rocker shaft should be free and clear of burrs and severe deposits

Rocker Arms and Shafts Disassembly/Reassembly — 2002 Honda Civic EX Coupe L4-1668cc 1.7L SOHC (VTEC) MFI Service Manual | Operation CHARM

Detailed repair manual for the 2002 Honda Civic EX Coupe L4-1668cc 1.7L SOHC (VTEC) MFI.

charm.li

charm DOT li is the website, it is NOT perfect, it does NOT have 100% of info wanted, but it does have something!!

 

Update. Everything looked good in the valve train. It is really clean and you could eat off the inside of the valve cover. I change the Mobil one synthetic oil every 3k miles and have done so since I installed the jdm engine with 33k miles.

On the vtec issue, I had tested the wiring i had ran to the ecm and it tested good with a continuity test. As I retested the solenoid wire for the third time, it broke off just before my soldered connection to the pig tail. Reconnected it and now the mil light will not come on and I am not in limp mode anymore, vtec is now working.

The intermittent tick/knock sound is worse now after the test drive. I laid into her pretty good to see if I could get the 2646 code to come back, it did not. I'm thinking I have an issue with the timing belt tensioner as that's the only thing over where I hear the sound. I have a new timing set on the way and will install on Monday. I'll update once installed and test driven.

Thank you to all that have helped me get this sorted. Almost there.

 

the valvetrain and head might be clean, but are all the valve springs in good condition? all keepers snug and not moving? retainers not scarred, burred, cracked?


Ive had to replace valvetrain components in recent years for a lot of local honda guys, and its stuff literally from AGE, not abuse.

 

This guy.

weak oil pressure, from a simple bad oring in teh oil pump. Just toss a new pump into it

The new oil pump will include the O ring and mounting face gasket.

There's no O-ring "in" the pump, there's one that seals the outlet passage to the engine block. There's no face gasket, it uses Hondabond/grey RTV. There is a small gasket between the pickup tube/strainer and the pump inlet.

When the ecm commands and the solenoid opens, how does the oil get to the locking pistons in the rockers? Is there an oil galley?

The rocker shaft is the galley - It's hollow. IIRC, a flow-limited (low-pressure) supply of oil is fed to the shaft when VTEC is disengaged, which provides rocker lubrication. The VTEC solenoid (the part with the steel can) + spool valve (chunk that the solenoid and switch are attached to, and bolts to the head) is a pilot valve setup. Oil flow from the solenoid valve itself drives the spool (round button-looking thing under the solenoid) downward, which uncovers the ports for the main oil passages, allowing full oil flow to the rocker shaft. Ports on the rocker shaft pass that oil flow to the spring-loaded split-pistons in the intake rockers.

Judging from the cam lobe count, lack of cam-followers and lost motion assemblies, the D17A2 is a VTEC-E engine. When VTEC is disengaged, one intake valve follows a mid-to-high RPM cam profile, the other follows a barely-opening cam profile that prevents fuel pooling on the back of the valve. This is 12-valve mode. When driven with enough pressure and the timing plate is out of the way, the rocker piston locks the two intake rockers together so that they both follow the mid-to-high RPM profile - 16-valve mode.

 

Fixed!
VTEC-E
After testing the wiring from the ecm to the solenoid and pressure switch, I decided to test again and the solenoid wire broke just before the joint I had soldered. Reconnected with a butt connector and now have VTEC engagement. P 2646 code is gone and VTEC is operating properly. I had tested the wires for continuity where I should have ohmed them out. The wire was incapable of passing voltage or current.

Knocking noise
During the oil pressure test I started to hear a knocking sound from the front of the engine. Sounded like a handful of nickels behind the timing cover and or valve cover. Noise was intermittent and did not follow RPM. Installed a Gates power grip timing set and it is quiet now. I couldn't find anything wrong with the timing belt, spring or the tensioner. I'm thinking the tensioner was bad under load. The timing belt and tensioner that were bad were factory honda parts I had installed on the engine when I did the engine swap and only had 53K miles on them. Fun fact, the factory honda belt I took off is stamped Honda and Gates. Sucks it only went 53K as I thought I should have gotten more life out of them. They decided to crap out as I was diagnosing the VTEC issue, naturally.

Thanks to all who responded. There are some great links in this thread on testing and VTEC-E operation I hope will help someone else in the future.


Cheers,
Chris