Jump to content
SAU Community

Recommended Posts

hey guys ive recently had more issues with my 30 just wondering if someone could help me out... recently the motor after an hour or so highway drive started to knock, I just can't understand why...initially i thought it was the hydraulic lifters or something as it sounded like it was coming from the head,it was fairly similar to the sound I heard when i first done the start up after a while of warming up it had gone away. I can't understand how it maybe a bottom end knock, as everything is acl race, forged pistons, shot peined rods, n1 oil pump etc motor was fully balanced and had a run in tune. I only had a standard rb20det turbo on there as I had just finished running it in and only just done the oil change. I cant understand what it may be the car did not over heat on the long trip or lose any power. Thinking back i do remember when i was bringing the car back from the tune at traffic lights the oil pressure droped dangerously low and when i gave it a few revs it went back up again so i kept the revs up on the drive back home, but since then it has never happened again (this would have been in the first 50km or so of fresh build).

I do not know what it can be, please help?!?!? :P The oil that i'm using is Penrite HPR 10

I've done a compression test on the motor and got between 110-120 across all cylinders, it may be slightly low maybe because of the pistons ive used or perhaps the head gasket?

any ideas or suggestions will be much appreciated I just hope I don't have to pull the motor out again.

Edited by Redliner007
hey guys ive recently had more issues with my 30 just wondering if someone could help me out... recently the motor after an hour or so highway drive started to knock, I just can't understand why...initially i thought it was the hydraulic lifters or something as it sounded like it was coming from the head,it was fairly similar to the sound I heard when i first done the start up after a while of warming up it had gone away. I can't understand how it maybe a bottom end knock, as everything is acl race, forged pistons, shot peined rods, n1 oil pump etc motor was fully balanced and had a run in tune. I only had a standard rb20det turbo on there as I had just finished running it in and only just done the oil change. I cant understand what it may be the car did not over heat on the long trip or lose any power. Thinking back i do remember when i was bringing the car back from the tune at traffic lights the oil pressure droped dangerously low and when i gave it a few revs it went back up again so i kept the revs up on the drive back home, but since then it has never happened again (this would have been in the first 50km or so of fresh build).

I do not know what it can be, please help?!?!? :P The oil that i'm using is Penrite HPR 10

I've done a compression test on the motor and got between 110-120 across all cylinders, it may be slightly low maybe because of the pistons ive used or perhaps the head gasket?

any ideas or suggestions will be much appreciated I just hope I don't have to pull the motor out again.

I had a noise in my 30 engine it was quite at idle and it got a knock a 2000rpm and it stayed the same all the way through the rev range. I pulled the engine out and found the it had spun a bearing, I had a fully forged bottom end and all the bearings. I also had a broken oil pump and it was an N1 and i still had good oil pressure all the time.

sounds bad to me....the first 1000klm of any motor are the most likely time for it to fail.

i'd suggest getting a good mechanical oil pressure gauge on there to check what is happening, but don't drive it anywhere or run it.

most likely a bearing clearance problem, assembly mistake, not cleaned properly or some oil pump failure.

I hope that you had a single mechanic responsible for the whole build, because getting warranty on engine builds can be tricky

Hey guys, I got told by a couple of people to do a leak down test on the motor (im not sure how to do this). In reply to Todoom just a question you know how you spun your bearing was the motor under any kind of load at all? It could possibly be my oil pump as I did use a N1 oil pump but in the rush i did not fit the collar to it expense mistake maybe?? :rofl:

As for assembly to Duncans comment well i was present there my mechanic friend was the one who put the bottom end together and I was there helping him assemble the whole thing...so yeah no warrantee there as it was more a favour unfortunatly lol I havn't driven it since it got home only started it a couple of times not running it for very long.

I guess all this is pointing towards me pulling the motor out and actually looking into it that way?? Are there any other possible tests or anything I could do before having to rip the motor apart? Is it possible to spin new bearings also?

Thinking back I did only use 1 1.5mm Restrictor on the block could this have lead to the possible bearings being F****ed

Edited by Redliner007

Hmm doesnt sound good. As Duncan suggested, get a good oil pressure gauge on the engine and see what is happening. It would be the first thing i would be doing as a test.

as stated above, sounds like oil pressure is an issue... you already mentioned you lost pressure once already.. if it were to lose pressure for a while it would result in damage capable of making a knock sound that only appears when oil pressure drops slightly.

the theory i am suggesting is that you now have a clearance issue on one of your bearings which is only evident when oil pressure OR flow is low a gap is created and you hear the noise.

or the pickup could be loose. Could be a myriad of things all of which the results could suck if left too long.. :)

Best bet is to drop the sump and look for play in the big ends (conrod) and pull a few main caps off too just to be sure. Thi swill tell you what is damaged.

in replies to the oil pressure issue, my question is wouldn't the knocking sound have come up alot earlier? As i mentioned that the pressure dropped within first 50km or so. But yeh looks like i will have to get the oil pressure gauge and perhaps drop the sump see whats going on.

TRENT you said "Could be a myriad of things all of which the results could suck if left too long.. " so pretty much i should get onto this as soon as possible? This did happen roughly a month ago now :S

well yes, it could have come up earlier, yet as ive suggested it could be intermitent and pressure/flow dependant. also the oil pickup as trent said could easily do that too, i have also heard of bad gaskets on oil pickups causing all sorts of issues.

so as stated, drop sump and inspect... but if not confident please get a mech you TRUST to do it, you need to retorque everything 100%. the original builder would be preferable for the job.

You could always do an oil test first. But any time someone suggests that, it always the last thing that happens

Chances are one of the bigend bearings has failed. If it happens in the first 1000km then you can pretty much look straight at your engine builder.

If one wasn't torqued correctly then it could be something simple like that. Either way, not a good situation

An oil test is something that all of you should be doing as part of routine maintenance.

They cost about $35 per test, results in about 48 hrs (usually) and they tell you everything - even if you have a dirty air filter

You can pick up an engine failure before it happens. I have done an oil test when pressure dropped 5psi. The test showed raised levels of lead and copper, we drove the car for a week and did another test, the levels of copper and lead increased so we pulled the engine down. Scuffing on the bearings and slight wear on the thrust bearing.

Absolutely no crank damage, bearings were all still intact but all showing signs of wear. We were able to get to it before it did any damage.

Unfortunately for this one, there is a knock, whcih means the damage is probably already done.

Hey guys, I got told by a couple of people to do a leak down test on the motor (im not sure how to do this). In reply to Todoom just a question you know how you spun your bearing was the motor under any kind of load at all? It could possibly be my oil pump as I did use a N1 oil pump but in the rush i did not fit the collar to it expense mistake maybe?? :P

As for assembly to Duncans comment well i was present there my mechanic friend was the one who put the bottom end together and I was there helping him assemble the whole thing...so yeah no warrantee there as it was more a favour unfortunatly lol I havn't driven it since it got home only started it a couple of times not running it for very long.

I guess all this is pointing towards me pulling the motor out and actually looking into it that way?? Are there any other possible tests or anything I could do before having to rip the motor apart? Is it possible to spin new bearings also?

Thinking back I did only use 1 1.5mm Restrictor on the block could this have lead to the possible bearings being F****ed

The motor was just under normal driving conditions when it spun i would suggest a crank collar and put the billet gears in the pump as the standard ones are very weak.

How much do you usually need to send em? can you simply mail off a sample or need to see them in person?

It's about 100ml - 150ml and comes with it's own return postage. You mail it off and they email the results

1. The leak down test is not going to tell you shit about the oil pressure or the knock

2. 110 - 120 psi is rediculous. Should be up around 150-160. If you have some kind of special setup or whatever they can be as low as 140psi

3. What did your friend use to measure the bearing clearances and who did the machine work on the crank and block?

we had an engineer who did all the machining work, we did use him in other engine builds and he all good. To be honest I cant remember if we measured the clearance at all of the bearings.

Sounds like the oil test is the way to go. I wonder if i could find someone local to do this for me. Is there a special name I should be looking for in the directory? I have spoken to my mate about the situation and he is happy to help its just that he has started a new job and is working 6-7 days so may be a long wait before anything even gets looked at. I'm not prepared to wait too long as I don't have a car anymore :P and him being in a different town isn't all that much of a help either lol.

If i were to pull the motor out AGAIN i'll probably be considering doing the following:

As Stuart mentioned the billet gears... I wasn't aware of this originally but hey if it helps with oil control thats a + in my books

also getting the collar done for the oil pump

may even consider getting forged rods if the pockets let me

Is there anything I should also consider doing when its apart?

also is 1 oil restrictor alright for the block? I didn't want to restrict both the oil galleries as I didn't want to staff the head too much.

Also what torque specs did you guys use for the bottom end? We used the r32 gtr settings I wonder if this could have been an issue also?

Edited by Redliner007

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
    • Can you also make sure the invoices on the box (And none exist in the boxes) are below our import duty limits... I jest, there's nothing I need to actually purchase and order in. (Unless you can find me a rear diff carrier, brand new, for stupidly cheap, that is for a Toyota Landcruiser, HZJ105R GXL, 2000 year model...)  
×
×
  • Create New...