Sluggish vp t5 v6

[gtrboyy]

Like Vlad kind of think harmonics are setting off knock sensor or it's got granny spec memcal.

Although bit hard not to expect more when last daily was modded vy ss m6 ute & weekender is low 11sec vh sle.

[vlad01]

Do you have extractors? if not get some pacemakers for it and a larger throttle body. If you want I can send you a tune to suit that exact combo, you won't regret it lol. Oh and a Mace CAI is a must and toss the bellmouth.

As for the noise, they typically make chattering noise, main source is the lifters, 2nd often but not all engines is the rear balance shaft bearings, some are just noisy from new, nothing physically wrong with them needle roller bearing tolerances etc, timing chain can rattle but not enough to hear without knock ears (knock sensor, pre-amp/filtering and headphones) and lastly and pretty obvious is the injectors and fuel lines pulsing. That's loud enough you can hear that inside the car.

[vlad01]

Re the removal of a belmouth, note this is a mild race engine so the delta will be less on a stock engine, but gains are gains.

Curve in green is the run without the bellmouth, good increase in areas under curve, especially mid areas.

[gtrboyy]

Yep it's got extractors(genie) thought they were factory for manual cars?
Changed cat to good spare one & replaced exhaust with new 2.5" catback cobra??? or some brand from gumtree
65 mm throttle body,gave it a good clean,chopped bellmouth up & refitted as it idled nicer with it
new engine mounts
v6 supercharged otr
new filters,oil flush
replaced o2 sensor to good spare v8 one..no fault codes since then
balancer looks new'ish no wobbles etc
replaced broken clutch pedal spring & few other things can't remember.



Checked for pulsating lines..all good.
Took timing belt off,noise still there..lifters & some timing chain IMO although it will probably get better with few more flushes/oil changes.
Top plastic tensioner is on it's way out..will replace with steel version & shorter belt to ditch air compressor.

Running it on 91 or 98 made no difference to idle or low end torque.

That's a shit ton of labour for $950 ute bought 2 months ago but strangely liking the damn thing.

[gtrboyy]

When under car you can hear resonating tinny sound like it''s from engine y-piece...that's probably balance shaft noise,more pronounced underneath car.

No exhaust leak as kept checking/thinking it was....although sounds nothing like old astron 4g54 when they did balance shaft.

Most of my holden experience has been holden eights & wild solid cam triple webbered 202 that rattled windows.

[vlad01]

No point oil flushing it, lifter go on them after 150K, they no longer maintain hydraulic action and bleed down. If you replace them, get LS7 ones ending with 490 part number. But once you do that, you'd need a new cam anyway because more than likely the old cam's hardening would have started to come off already and you'd trash the new lifters.

Also you'd need the correct length push rods to suit. Can of worms really. They still work well past 400 and even 500 and beyond but just not optimal and noisy.

I recall the genie extractors were rather short primaries? Pacemaker definitely had the best tuned extractors of stock to mild V6. I have tested shorter ones like hi-tech and hurricane and they weren't much better than case manifolds, pacemakers on the other hand certainly made a big difference.

2.5" cat back make a slight improvement, but the extractors makes 80-90% of the gains in the whole system on a stock V6.

Toss that OTR CAI, I found them worse than a stock airbox with no snorkel piece attached on the bottom of the box I had an issue with lost power years ago and I spent months chasing my tail, was the damn OTR I fitted that caused it, removing that and running engine bay air if a vast improvement over stock or OTR, but best results are from a MACE style CAI. I did some data logging and testing comparing stock and a MACE and the improvements were way beyond was was marketed to the product. The factory air box is a POS and deserves to go in the bin.

Problem with the OTR is it wasn't designed for the VN/VP body where the bonnet blocks the intake and that was exactly the issue, also the whole additional plumbing and bends don't help.

65mm TB will do just fine for stock, its not a big gain but its measurable.

[immortality]

Vlad, how often do you change the oil and do you use good quality oil? I'm just wondering why your engines always suffer from failed lifters?

I have a early VN engine in the garage, I believe it was well over 200,000km when I stripped it. Lifters were fine, rollers and cam look perfect with no lifter noise etc. I did find the chain tensioner in the sump which was the source of the extra engine noise it did have.

[MAGP]

I was doing my Apprenticeship when these things were new (well the VN anyway) and worked for Holden when the VP was being sold as well and never come across failed lifters. I also had alot to do with Lexcens for the local Toyota dealer because no one else wanted to work on them. Taxis would rack up huge mileage in the SE of SA (travelling from town to town because public transport was pretty crappy) and I never saw any issues with lifters. The taxis used to follow Holden's normal service routine although some used to do oil changes half way but for no good reason cause they were on LPG and the oil was always clean.

The one big, internal, problem the early Buicks (VN1) had was valve seat recession but Holden fixed it eventually with hardened seats. Apart from that they were a leaky, noisy, harsh, engine that were rushed into the VN because the Aussie dollar collapsed (thanks to Paul Keating) and the RB30 was to expensive to source from Nissan.

[immortality]

Nothing wrong with those early VN's, they went hard compared to the later ones

I still think my VN V6/T5 was more fun to drive than a V8/auto model. The standard 4 speed slush box really suck.

[delcowizzid]

Snapped chain tensioner makes them rattle but even that doesn't kill much grunt on a series 1 lol we have 300000km plus lifters on our re ground cam still holding in there and quiet as a mouse lol