1996 Q45 rod knock or chain guides?

[lowmax97]

I have a 1996 infiniti q45, currently at 103,467 miles

here's the run down :

About a month prior to the noise occurring, the car over heated due to a coolant leak, i immediately pull over and shut the car off ( a chime went off alerting me the car is overheating). So i all AAA and have my car towed cause i didn't wanna cause further damage.. Next day i have the car fixed, ( radiator cracked) i do an oil change the same time cause it was due for one. Ok that's done.. 2 weeks down the road, i had to go to work in the morning, and i start the car up, and i hear this rattling noise, i shut the car off, and i check the oil, oil level is fine, all fluids are ok. i take my GF's car to work cause she was off and i didnt want my engine to blow or anything. I come home.. i start the car up.. and the noise is gone.. , so i drive it for a week, its fine and smooth, and i make sure the noise is not there when i drive it. Now it came back, and its not going away, it sounds like a rod knocking or it could be the chain guides.. Im putting my finger on the chain guides and cause the noise is right around there.

Heres the weird thing.. the oil light stays on.. even thought the oil level is completely fine.. could it be the oil pressure sensor switch.. or the oil pump failing.. I just want your guys input before i do any costly work on it,

i attached a video so you guys can better understand the noise.

Thanks for any help or input into this.

http://www.youtube.com/watch?v=Nqtyx7uG7UI

[Q45tech]

If oil light is on the PSI is below 3 not the 15 minimum required!

Over heat can cause bearing damage and coke the oil blocking the pickup in pan.

Normally one first checks oil sender for continuity, then pulls a valve cover and looks for damage [oil varnished or sludged, then pulls the oil pan looking for a blocked strainer. Pull front cover and view chains and guides, especially replace oil chain to remove the stretched unit.

Do what ever is necessary to get oil pressure back to spec...............14 psi with new oil and filter as measured with an accurate oil pressure gauge.

I'll bet poor oil changes prior to overheat caused previous damage.

The previous 13 years should have had 13 x 4 or 52 oil changes. Do you have records reflecting this frequency.

I'll bet with only 103k only biannual oil changes were the norm ~~ 25-26.

We have seen many [especially 96 Q] destroyed by annual oil changes, not the every 90 days as recommended.

Time to bury the remains as you have already cremated the engine.

Poor mainteances allowing an overheat is an almost sure method to detroy a precision all aluminum engine.

[lowmax97]

i bought the car at 96XXX from a infiniti dealer, I checked oil the day that i bought it and it was good oil ( clear and unburnt) i did oil changes ever 3000 miles, not over that, i dont know how long it was running with out coolant, but i all ways check my gauges every now and then when i drive.

but what could of caused this damage, suffocation of oil, or just over heating?

[qship96]

sounded like typical injector noise or HLA noise to me?

At 8000 miles per year, every 6 month 4000 mile changes would not have damaged engine in any way, shape ,or form with todays quality oils and filters- the 3 month/3000 mile interval is a crock with todays oils and engines.....hard for old timers to swallow this

[Infinitiguy19]

But you mean synthetic oil not dino oil right?

And I agee with the HLA or injector noise, But I am more torwards HLA for obvious resons.

[lowmax97]

not to be a newb.. even though i am

but what does HLA stand for? LOL

and yes mobil 1 oil and filter.

[Infinitiguy19]

Read this: http://www.nicoclub.com/FSM/Q45/1994_Q45/em.pdf

Then the rest of the FSM AKA service manual here: http://www.nicoclub.com/FSM/Q45/1994_Q45/em.pdf

Welcome to NICO.

[Romeo5k]

I say check chain guides IMMEDIATELY. Then oil pressure switch and oil pump. That noise sounds very familiar. I think my car was suffering from bad injectors and i kept riding with no knowledge. And car did that. Shortly after a few more starts it did not want to start again. Found out, oil pump went out. Which also chains were damaged as well What a 93.. But check ur stuff, dont drive it anymore unless u want to salvage ur parts.

[Infinitiguy19]

Nope my guides are semi confirmed to be replaced, because of service history and red RTV.

Service history says: Car was towed in because drove through ddep water and threw rod #7, replaced all gaskets and seals at 39.xxx miles.

[Q45tech]

Of all the 94-96 series we have seen more 96 engine failures for some reason even though the 96 represent less than 20% of the total engines sold.

Everyone of the failures was overheated and had bad oil change habits.

For some reason maybe the new purchasers were less reliable or technological than the early model purchasers. Everyone admitted to lazy oil change habits and said "Modern oils/engines should have been able to TAKE IT"...................funny this is the same line of bull**** that all the Lexus engine replacement jobs expouse.

So for 96k of its 103k you have no proof of its prior abuse or 13 years of service..................other than a dealer sold it in the end...............now go back to them a get copies of the computer print outs and piece together the real history.

[lowmax97]

i wis i can go back to get the service guides, but the infiniti dealer closed due to no sales i guess. The only maintance records that i have was all the way back to 67,443, that was for a alternator and belt.

72,543 - water pump - replaced cause of leak74,059 - Front brakes and rotors78,236 - Oil change - walmart85,679 - Diff oil change

and thats all that came with the car.. sorry for the lack of records

The check engine light just came on, so im gonna pull codes first thing in the morning, and ill post the codes that came up.

thanks again for you help guys

[maxnix]

i wis i can go back to get the service guides, but the infiniti dealer closed due to no sales i guess. The only maintance records that i have was all the way back to 67,443, that was for a alternator and belt.

If you have not cultivated a realtionship with a good Infiniti service writer or manager, call Infiniti Customer Service and register your self as the owner of the car. They can read the service history to you over the phone. Painful, but better than nothing.

[unknown007]

Drop any tools in there?Other than that i wish for the best.