Injectors misbehaving but trying to understand the numbers

[darbuck]

I was just down lapping the valves and is covered this on the cylinder 3 exhaust valves. I think I need to replace it any thoughts.its a small dent in the valve seat face

[Steve Walsh]

Hard to tell from the photo, but an engine machine shop might be able to re face it. Or stick a new one in for piece of mind. You are so far into it, be a shame to spoil it now....

[Paul-R]

That pitting is not good. As Steve says, it might be possible to reface them but better to replace I think.

[darbuck]

Yes I have decided to replace both exhaust valves on that cylinder the other one is slightly out of true. There's a bit of wobble on it when rotated. It's the only one that does and given the pitting on the valve in the picture I think it would be prudent for the sake of €30 to replace it. These valves are from the cylinder with the bad injector it seems like something was going on in that cylinder possibly because of the valves/injector. Either way I think I caught it before it became a bigger issue.

[MattBLancs]

Very odd, ingested something? Low speed timing belt snap? Quite a puzzle.

Was some minor pitting in the DV6 valves from memory, but nowt bent or with chunks out thankfully!

Gosh, it's not being kind to you this bugger, eh?

[darbuck]

No it just keeps giving . Nearly there now, just waiting on a few parts to complete the puzzle. It's a weird sort of a thing, all the problems are in cylinder 3, injector, bad valve and excessive carbon build up. Should be ok once I put it all back together. I believe my injector seal extractor just arrived so I can finally get that port finished for once and for all. My engine is sitting on the driveway as you know and covered but my bloody dog got hold of two connectors on the loom and chewed the cables so I have wiring to do now .

[darbuck]

Hi lads a few pics of the head, I am slowly getting through it I have two valves left to do. Waiting on replacement to arrive now to continue rebuild

[KennyW]

Keep up the good work Darren. I think what you have found explains the problems you were experiencing earlier plus the additional work on the rack.
Once rebuilt it will run like a dream. A new car!

Kenny

[darbuck]

Hi Kenny, I agree I think so too I am going to pull the sump when I have it put back together and give it a clean aswell I think overall it will be a great car when I am finished

[vallium]

I'm a bit late to the party but somebody might find it useful. Recently, while doing glow plugs, I've became a bit of an evangelist for 50/50 Acetone/ATF oil mix.

All 4 were blown and with crappy location they're in I was pretty worried either plug or its tip stuck in carbon might break. After application of said mix with paintbrush for about a week they all released with less than 15 Nm (did use 1/4" digital torque adaptor) and unscrewed smoothly without squeaking. It also turned carbon on neck of one plug into black oily substance.

Later I did the same on stuck brake calliper bleed nipples. Liberal application of either butane torch heat/cold water or off-brand Lidl WD40 (otherwise IMO better than real deal) didn't help them budge, fore mentioned mix did it tho.

[darbuck]

Thanks for that vallium.

I have just put the last two valves into the head now, just need to do lifters and rockers.the hardest part is the colletts but with patience a magnetic screwdriver and a tub of vaseline and a windy valve spring compressor it's not too bad. I am hoping she will run well now when I put her back together.

[MattBLancs]

Has the head been skimmed? It's a cracking clean up job you've done if not!

Know what you mean about the valve collets, on my DV6 job I used grease rather than vaseline and also stuck it to the screwdriver with grease (instead of magnetic) as well as a splodge on the valve stem ridges. But it seems an endless job! Cylinder head on a nice high table, and a stool or chair to sit on and just "potter" through it.

Suppose just be grateful it's not a pair of V6 heads to put all the collets back into!

[darbuck]

Hi Matt, no it's just a plastic scraper scotch pad and 1500 grit. Just being my OCD self. Took nearly a week of evenings, just taking time to finish it off but I am happy it won't leak. No gaps under the straight edge. I have a V6 Maxima lurking on the driveway that might need this aswell.

[MattBLancs]

I don't think there's much in the engine bay that would ever suffer from being "too clean" - so I say let your OCD cleaning tendencies to their own devices and reap the rewards!

I like to clean stuff up when I come across it, almost invariably repainting rusty brackets, reinstating missing clips (or conversion to something else, e.g. no more useless plastic clips on my my wheel arch liners = riv nuts and bolts + penny washers) All good

[darbuck]

Nothing wrong with that . I'll do a bit more tonight. I pulled the subframe out and power hosed it down. Repainted cross members and anti roll bar. I have to replace the thermal sound proofing aswell. So I will clean up the engine bay aswell while I am at it.