Nissan AD VY11, QG13DE, Engine Head Problem (Plz Advice)

[first_blood]

Assalam o alaikum dear Pak Wheelers,

I am a silent reader of this forum for quite a time and I found it very interesting. I have an JDM Nissan AD 2006 regd 2012, 1300 cc having QG13DE engine with A/T. The car has completed 215,000 kms on the ODO and till last month it was running on original engine (without any rebuild).

For the last 3 / 4 months, I observed that car losses its power gradually by the time and vibration in engine at idle or low rpm. The car moves to & fro (jerks) when stopped on signals/traffic while in D position. The jerking is quite high and I have to bring the gear lever to N while the car is stop. The car has no cold/hot starting issues and always start in one self. no overheating history, thermostat valve is in place and fans are auto. In Pakistan, the car is mostly driven on CNG (almost 100k kms). IMO Overall engine is in good condition having no engine oil loss, blue smoke, carbon deposits at silencer end, smooth engine sound etc.

Last month, due to missing, vibration and lack of power, my mechanic advised me to rebuild its engine head with new valves, valve seats and machining etc. I followed his advice and rebuild engine head with new taiwan valves set and related stuff, the machining was done at Al-Madinah Engineering at water pump. After dis-assembling, we have found one exhaust valve seat burnt and that particular cylinder was misfiring. After rebuild, i observed that the engine missing/vibration has gone and power is restored to an extent (but not completely) I notify the matter to mechanic but as they all said, it will be better with time (and it doesn't).

Now the condition is, the car performs well for 6k kms after the rebuild and during the last week I started observing slight vibrations in engine, car also vibrates/jerks minutely when stop in D position. The missing can be heard at exhaust tip also. The mechanic is so dumb he cannot feel the vibration and missing and advice me to either increase engine RPM through software or ignore it, its all normal. (well IMO its not). I think valve seat(s) is/are damaged again and we have a loss of compression in cylinders. My car mostly driven on National Highway within speed of 80km/h to 120km/h. I use Havoline Formula 10W30 for this engine with guard oil filter.

Kindly advice guys, i am so fed up with these mechanics. Should I have to rebuild head again, or make adjustments in valve shims by grinding them a little. I am also thinking of replacing complete kabli head from shershah, they are asking 22k for it.

Kindly also advice, do we have some special valves and valve seats for use in CNG vehicles, as i heard form many that CNG produces high temperature in combustion chamber hence burn valve seats.

I will be very thankful to you guys for your concern.
@xulfiqar bhai, @spectra, @capsat (your advises are critically required).

[first_blood]

?? waiting for your response guys.

[first_blood]

[capsat]

immediately change the transmission fluid

am not sure which city you are located, Obama car care Tipu Block, Lahore can do the job nicely.

[argtr65]

This is all happening because of incorrect valve clearance,Al madina engineering is not capable to perform machining work on sophisticated engines.Its better to redone head work by Malik engineering at radio Pakistan,if needed.
There is no special valve assembly for use on cng,For cng valve clearance should be kept on plus side by .005mm w.r.t specification.

[ahmed2396]

Nissan engines wear very slowly, and are very reliable. I would advise you to do a compression test. Most of the times timing chain wears on these engines after 150k kms, engines has lack of power and jerks too.

[first_blood]

Thanks capsat, the ATF was replaced some 15k kms back and is ZIC ATF III, however i will replace it on coming sunday. I normally replace ATF at 15 - 18 K Kms intervals. The current condition of ATF is not blackish and look reasonably clean.

[first_blood]

This is all happening because of incorrect valve clearance,Al madina engineering is not capable to perform machining work on sophisticated engines.Its better to redone head work by Malik engineering at radio Pakistan,if needed.
There is no special valve assembly for use on cng,For cng valve clearance should be kept on plus side by .005mm w.r.t specification.

Thanks dear, actually i handover my engine head to AlMadina engineering at water pump karachi as it was advised by few friends and the mechanic. From the very first day after rebuild, I does not feel the power in the engine which it had when I bought the car but the mechanic insists that it will be better with time, valves make their place on seats bla bla. I ask about special valves as this engine also came in CNG versions in japan. i.e.QG18DEN so i thought may be there are any valves for LPG/CNG applications. I will go for the rebuild if the matter is not sort ed out soon, because car behaves very bad (Shaking the whole body) when in stop position.

[first_blood]

immediately change the transmission fluid

am not sure which city you are located, Obama car care Tipu Block, Lahore can do the job nicely.

I am in Karachi brother.

[first_blood]

Nissan engines wear very slowly, and are very reliable. I would advise you to do a compression test. Most of the times timing chain wears on these engines after 150k kms, engines has lack of power and jerks too.

Thanks for your concern dear, from where in karachi compression test can be performed. I also want to know the whereabouts of some good mechanic who can reliably work on nissan engines. The timing chain has no abnormal sound infact one cannot hear any noise from timing Chain. During the last head rebuild, the chain look clean and nice and it was also cleared by that mechanic. However, I will keep it in consideration if goes for 2nd rebuilt.

[first_blood]

This engine head is lean burn aluminium construction, can it be rebuild successfully by machinist available in Karachi.
What about head assembly from shershah (Kabli), but i have no experience how to check head at shershah. If it wont work nicely my whole money will be wasted as they did not return sold parts. He may replace it with another head but question remains whether its worthy or not.

Regards,

[IsbCap]

How much you spent in total? Your best bet was to throw in a QG18DE or QG15DE. Much more powerful and better fuel economy. These rebuilds are waste of money most of the time.

IMHO QG13DE is too under powered for this heavy chassis.

[first_blood]

How much you spent in total? Your best bet was to throw in a QG18DE or QG15DE. Much more powerful and better fuel economy. These rebuilds are waste of money most of the time.

IMHO QG13DE is too under powered for this heavy chassis.

Thanks for reply. Dear I spent around 20K on head rebuild including labor, machinist, valves set, gasket and oil etc. My engine block (i.e pistons, rings and bearings) are in good condition, no engine oil loss, smooth engine sound etc. for that reason I go through that head rebuild. Isnt QG18 is quite heavy on fuel (petrol) and if I go for CNG on QG18, can that engine withstand CNG heat or it ended up like my QG13 engine. Another thing which I am wondering, can QG18DE engine be mate with existing auto gearbox and ECU or I have to purchase complete setup (Engine/gear/ECU and harness).

[IsbCap]

Thanks for reply. Isnt QG18 is quite heavy on fuel (petrol) and if I go for CNG on QG18, can that engine withstand CNG heat or it ended up like my QG13 engine. Another thing which I am wondering, can QG18DE engine be mate with existing auto gearbox and ECU or I have to purchase complete setup (Engine/gear/ECU and harness).

QG18 would most probably give you better mileage than QG13 due to better power to weight ratio and running at lower RPMs. It's got huge low end torque and superb economy.

Recently many QG15 and QG18 swaps have been done. My QG15 gives around 12-13kpl in city and 16+ on long. QG18's have been reported to give almost same figures. And yes, QG's run great on CNG, too.

And most likely it would be bolt on with your existing transmission and wiring. Complete engine with gearbox and wiring should cost between 50-55K. If you have to rebuild, you would have spent 40K with still many old things in the engine and low power

@dani_kk @star2, Please guide the OP for engine swap or rebuild options.
@spectra already done QG13 to QG18 swap on his N16 sunny, so he can guide you better

[capsat]

no need to change ATF of it is 15000 km old. ATF life is over 65000 , new CVT transmission oil change is recommended at 75000+ kms - Guard is worst oil filter for JDM engines please get leppon or vic oil filter & use aisin or shell helix engine oil. if you are in Karachi Goto Jamil Autos at Shahrea Quaideen Society office +92 300 9232821 / PTCL 34761699. 10 am to 7 pm week days only

Thanks capsat, the ATF was replaced some 15k kms back and is ZIC ATF III, however i will replace it on coming sunday. I normally replace ATF at 15 - 18 K Kms intervals. The current condition of ATF is not blackish and look reasonably clean.

[first_blood]

QG18 would most probably give you better mileage than QG13 due to better power to weight ratio and running at lower RPMs. It's got huge low end torque and superb economy.

Recently many QG15 and QG18 swaps have been done. My QG15 gives around 12-13kpl in city and 16+ on long. QG18's have been reported to give almost same figures. And yes, QG's run great on CNG, too.

And most likely it would be bolt on with your existing transmission and wiring. Complete engine with gearbox and wiring should cost between 50-55K. If you have to rebuild, you would have spent 40K with still many old things in the engine and low power

@dani_kk @star2, Please guide the OP for engine swap or rebuild options.
@spectra already done QG13 to QG18 swap on his N16 sunny, so he can guide you better

You are absolutely right about engine rebuild in pakistan. I will check shershah market this weekend for QG18DE engines. Lets have some opinion by @dani_kk, @star2, @spectra and essentially by @xulfiqar bhai. AD van VY11 almost shares every thing on front with N16 sunny. By the way is it advisable to swap whole engine + transmission just due to bad engine head. Shouldn't I replace the head only from scrap. I might probably resolve my issue and will be cost effective too. Kindly advice.

[first_blood]

no need to change ATF of it is 15000 km old. ATF life is over 65000 , new CVT transmission oil change is recommended at 75000+ kms - Guard is worst oil filter for JDM engines please get leppon or vic oil filter & use aisin or shell helix engine oil. if you are in Karachi Goto Jamil Autos at Shahrea Quaideen Society office +92 300 9232821 / PTCL 34761699. 10 am to 7 pm week days only

Thanks @capsat for your concern, I usually change ATF between 15 to 20 k kms due to usage of ZIC ATFs, I am not very confident on ZIC lubes, i consider it due to its low price, however it works fine for 15k kms and after that mileage the gear shifts feels slight jerky. The reputed/branded oil filter for this engine is hard to find, during the last five years of usage i never find VIC, Nissan or Leppon filters for this engine. Some xxxxxx brothers (I forget the first name) and guard filters are available and mostly they are of Hyundai Santro.( Santro and AD 2006 oil filter are same)

I will try to visit Jamil autos this Saturday evening, Currently I am out of Karachi and will go to Karachi on weekend. I will update after the visit.

In shell Helix, which viscosity you recommend for this engine, Can I use synthetic oil for this engine (some 5w40). The ODO is 215k kms. I remembered, when I first drain oil which comes filled in vehicle from japan, it was as thin as diesel.

Does Jamil Autos have compression testing equipment, I want to get these readings before making any decision.

Regards,

[IsbCap]

By the way is it advisable to swap whole engine + transmission just due to bad engine head. Shouldn't I replace the head only from scrap. I might probably resolve my issue and will be cost effective too. Kindly advice.

Yes, for you the best option at this stage would be to change the head only. Negotiate the price well, head only shouldn't be too costly.

[first_blood]

Yes, for you the best option at this stage would be to change the head only. Negotiate the price well, head only shouldn't be too costly.

Shershah scrapies are looters, during the last rebuild, i visited shershah before disassembling of head from engine, I found same engine on two shops, they ask for around 14k to 15k without exchange of old unit. When I visited them again after disassembling about 2 weeks later they started asking 22k for the head without coils etc. both shops increased the prices as according to them there is shortage of nissan QG engines in market. They recognized that I have already disassemble the engine and now I am "majboor". To make a deal I have to purchase the unit first and then go to mechanic for replacement.

What is the expected price of QG13DE head in pindi (Bilal gunj) as i heard there are plenty of units available in pindi & peshawer markets.

[IsbCap]

Shershah scrapies are looters, during the last rebuild, i visited shershah before disassembling of head from engine, I found same engine on two shops, they ask for around 14k to 15k without exchange of old unit. When I visited them again after disassembling about 2 weeks later they started asking 22k for the head without coils etc. both shops increased the prices as according to them there is shortage of nissan QG engines in market. They recognized that I have already disassemble the engine and now I am "majboor". To make a deal I have to purchase the unit first and then go to mechanic for replacement.

What is the expected price of QG13DE head in pindi (Bilal gunj) as i heard there are plenty of units available in pindi & peshawer markets.

Transporting from Pindi to Karachi may not be too good an option.

And btw, have you scanned the error codes and ruled out any sensor faults/ misconfiguration before concluding that surely head is the culprit?

What are idle RPM values?