2003 engine overhaul ?!!

[abaddon]

Last week I took my car to the dealership because i was getting weird engine noise. they told me the noise is caused by low oil level and they will check the cause of having bad oil consumption on my 2003 Q45. The car has done 50k miles. I've just came back from the dealership and i was informed that I have 6 cylinders with low compression because of damaged piston rings. The car run smoothly but i feel like i lost some power. They told me that I have to replace the damaged piston rings and do an engine overhaul.

should I do the overhaul? because I heard that when you do an overhaul with re-bore you face some problems later on.

Did anybody got the same problem?

[maxnix]

Not under warranty? In the US the dealer will do an oil consumption test and replace the long block if defective. Doubt your local dealer has a dedicated machine shop required to rebuild a VK45DE.

What's your OCI history?

[Q45tech]

I would be concerned with the crank and rod bearings if you ever allowed the engine to run more than a quart low of oil.All the tweeks done to increase 4.5 liter power from 280 to 330 HP [reductions in friction] don't compute with long term reliability and durability.

These engines require a level of lubricant attention much higher than the old VH45 due to non leaded bearings and light ring tension. Failure to change oil every 90 days EXACTLY has done you in.

What you want is a new short block at minmum and a new long block would be ideal.

Not sure many dealers are qualified to work to oem factory standards of new build precision?

But then again you have gotten 50k out of it and 100k would be good if reringed and new bearings?

Good luck and try really hard for a new engine and this time take better care of it CORRECTLY.

[abaddon]

The car is not under warranty and the extended warranty has finished 2 months ago.

I will try to look for a new engine. Does anybody know how much a new VK45 costs in the states?

I have the compression test results.

2 cylinders are running on 10 kgf/cm23 cylinders are running on 11 kgf/cm21 cylinder is running on 12 kgf/cm21 cylinder is running on 13 kgf/cm21 cylinder is running on 14 kgf/cm2

so is it safe to drive the car in this condition for a while.

I dont have any records on the oil consumption, Ill run an oil consumption test after 1000 miles.

[Q45tech]

By now the JDM exporters should have VK45DE available for export and junkyards in US should have some wrecked FX45. M45, and Q. But tranport to Mina Sulman might be expensive.

The rings have been a problem since the 2002 redesign and it is luck of the draw unless extraoxdinary oil changes were done.

[marksport]

By now the JDM exporters should have VK45DE available for export and junkyards in US should have some wrecked FX45. M45, and Q. But tranport to Mina Sulman might be expensive.

The rings have been a problem since the 2002 redesign and it is luck of the draw unless extraoxdinary oil changes were done.

If you are in the Middle East, you've got the higher output VK45 that we didn't get in the US. if I recall, it's 365hp so about 25hp more than the US model. ME models apparently have better cams and tuned ECU to match.

[Kiven422]

14 kg/cm2 = 199 psi10 kg/cm2 = 142 psi

incase anyone's like huhhhh?????

[abaddon]

Does anyone knows what are the normal figures for the compression pressure?

[goody90q45]

Does anyone knows what are the normal figures for the compression pressure?

Here's a link to your Factory Service Manual:

http://www.nicoclub.com/FSM/Q45/2002_Q45/

From the FSM, page EM55:

(Kg/CM2, PSI)

Standard......13.5, 191Minimum.......11.5, 164Difference.....1.03, 14btwn cylinders

[abaddon]

So that means I have to do the overhaul or look for a new engine?

I have one question one of the cylinders has pressure of 14 kgf/cm2 and the standard is 13.5 is that normal ?

[goody90q45]

I'm guessing that your mechanic gave you back round numbers more to show the range rather than specific psi. I bet if you (or he) redid the test with an analog gauge you could interpolate the compression to be closer to 13.5 or use a digital tester.

We'll have to let one of the experts chime in on whether to rebuild or replace.

[maxnix]

If you are in the Middle East, you've got the higher output VK45 that we didn't get in the US. if I recall, it's 365hp so about 25hp more than the US model. ME models apparently have better cams and tuned ECU to match.

Good money is betting it's just a different rating system.

[Q45tech]

Depends on the per hour charges as you need to pull the engine either way to remove pistons to change rings and all bearings.

The lead free narrow bearings are "Green" but not robust and require perfection in oil changes [something non race car owners and non automotive engineers are unfamiliar with]. People use to old Nissan reliability are in shock with the new designs. Toyota and others are having similar problems.My quess is the bearings and rings [to boost power output] have halved the peak life of many engines and cut them down to a quarter with bad oil change habits.

Be prepared for 100k life if you try to treat new designs like the old 1990-2000 versions.

No free lunch on ragged edge HP boosts.

Back in 2002, 2003 I warned buyers to be careful of these new engines and treat them RIGHT, but alas. Nissan is still decently happy as most make ith thru warranty."Against the background of the European directive to banish lead from the automotive industry, MAHLE has in its current portfolio lead-free aluminum-based as well as bronze-based high-performance alloys for bearing and bushing applications. New three-layer bearings, which are being implemented or are currently under development, include entirely lead-free sputter bearings as well as innovative thermal sprayed and electroplated coatings based on lead-free bronzes."

"Durability is less of a concern today because the aftermarket and OEMs demand bearings that can last 150,000 miles even under severe stress from a neglectful vehicle owner."

"The tri-metal bearing is substantially stronger than a bimetal aluminum bearing, by around 30 percent and it’s more forgiving of crankshafts that aren’t perfectly round, smooth and straight,” says McKnight. “Bimetal aluminum works really well if everything is perfectly smooth and true?"Today, we have a material called A-590 which is totally lead-free. It’s a very strong bearing, almost equal to our basic trimetal bearing (H24).

http://www.sae.org/technical/papers/200 ... co....aspx

[maxnix]

The lead free narrow bearings are "Green" but not robust and require perfection in oil changes [something non race car owners and non automotive engineers are unfamiliar with]. People use to old Nissan reliability are in shock with the new designs. Toyota and others are having similar problems.My quess is the bearings and rings [to boost power output] have halved the peak life of many engines and cut them down to a quarter with bad oil change habits.

Be prepared for 100k life if you try to treat new designs like the old 1990-2000 versions.

I wonder how BMW is gettting by on 15K OCI? I'd never buy one off lease, that's for sure. Recyclable cars means diposable cars.

[Q45tech]

Obviously you are not keeping up on BMW Forums around the world"Read this BMW letter to owners:http://www.dtmpower.net/forum/....html

Synthetics plus a larger sump in BMW

[abaddon]

I guess I'm really shocked to hear about the new Nissan engine's reliability, I'm used to the old VG engines reliability. I own a VG30s car which done more than 200k miles ( touch wood ).

I'm surprised while Infiniti didn't make a recall or a TSB regarding the piston rings on the VK45 engines. As we all know its a major problem and this engine is used in many cars ( Q45,Fx45,M45 ), while BMW changed the bearings on the S54 engines and its only used on M3!!

[Q45tech]

What it is, is what it is no point moaning just adjust your buying and maintenance habits. Short sighted Americans caused this shift, by creating the HP wars.................Toyota has always lagged behind a little to maintain durabilty and even then look at their V6 crap.

They just don't [can't afford] to make them like they use to with all the EU recycle mandates.

Compare cat life now to then................my almost 19 year old Q with 320,000 miles still passed dyno emissions test very well.