# BLOWN head gasket on 2002 nissan sentra 1.8



## miguel83 (Oct 13, 2009)

Hello guys and sorry if this is a double or triple post. I have search the forums here for a couple of days and I havent gotten any answer to my specific question therefore i figuere i better post it up before i make a bad decision. 
I basically have a blown head gasket, my car has 106,000 miles on it. Which in my opinion thats not that many miles for a NIssan.
My question is... how involved is it to change a head gasket, is there a manual in particular that really helped you do the job if you have taken on this task? I have the dealer manual but i think is too detailed and im not sure i understand all the they are saying for example there is a piece on the manual that says something like
*set NO. 1 piston at TDC on its compression stroke.:wtf:*
I mean there is got to be something a little simpler then this. I've worked on car for years adding and removing part but this just sounds like its crazy. can someone please help me. I cant afford a new car and i dont want to pay the dealer 1200 to do this job which im confident i can acomplish on my own.
Thanks in advance 
everyone


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## miguel83 (Oct 13, 2009)

BUMP
can anyone throw me a bone on this one?:waving:


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## pulsar86 (Aug 13, 2009)

All that number one cylinder on compression stroke means is that the cylinder in number one bore is at the top of its stroke on compression [all valves on that cylinder are closed. This is very important for setting the timing and putting on the timing belt with all of the timing marks correctly aligned. All manuals will have a similar instruction. The factory manuals are a little harder to follow than some others. Just make sure you fully understand everything before starting work and you should be ok. Best of luck.


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## miguel83 (Oct 13, 2009)

pulsar86 said:


> All that number one cylinder on compression stroke means is that the cylinder in number one bore is at the top of its stroke on compression [all valves on that cylinder are closed. This is very important for setting the timing and putting on the timing belt with all of the timing marks correctly aligned. All manuals will have a similar instruction. The factory manuals are a little harder to follow than some others. Just make sure you fully understand everything before starting work and you should be ok. Best of luck.


thanks Pulsar i just bought the haynes manual for the nissan sentra. it looks a little easier to follow but im not sure . Anywho I'm going to continue to study the book and hope i can get this done.
Thanks for the reply.


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## IanH (Feb 11, 2003)

Search and read some more.
One tip is to zip tie the chain to the cam gears so they dont move, make re-assembly and timing the camshafts easier.
Good luck.


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## miguel83 (Oct 13, 2009)

Thank you eveyone for the replies thus far. Does anyone know if i have to remove all the pullies on the side of the car or just the water pump pullie. I have removed all the belts and drained all fluids and pretty much disconect all electrical. and i have also remove the valve cover. now im at a standstill because I just dont know what to do next. do i start taking the cams apart or do I know i have to remove the front exhaust tube do i just remove the 4 bolts at bottom of the car? sorry for all my stupid questions i just hate to have to remove parts that at the end were unnessesary to remove...
Thanks everyone.


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## IanH (Feb 11, 2003)

I haven't done this to this engine but recommend you follow the FSM or haynes manual.
give me a few minutes and i will see what i can find


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## IanH (Feb 11, 2003)

I dont have this FSM, If I get time I will research and reply late tonight.


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## miguel83 (Oct 13, 2009)

i have the manual hell i'll even give you the manual if you want. but its not very clear... this is why im confused. i really appreciate you taking the time to reply to my questions i never felt so losed in my life.
Thank you.


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## IanH (Feb 11, 2003)

Ok how far are you down this list, more to follow


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## IanH (Feb 11, 2003)




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## miguel83 (Oct 13, 2009)

im on number 5 right now because i have two problems what is the front exhaust tube? it says to refer to ex3 but nothing on the chapter calls it front exaust tube... then i also have a problem with the timing chain do i have to remove it. Man i hope this post helps someone else down the line. this is almost a walkthrough. rocker bolts have been removed and that rocker is already off... you are the man IAN
thank you.


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## IanH (Feb 11, 2003)

#6 disconnect the exhaust from the bottom of the exhaust manifold.
once all the intake connections are free it says remove exhaust manifold.
rear intake supports are underneath the intake


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## miguel83 (Oct 13, 2009)

*PHEW I got the head off.*

OK guys the head is off :waving: i must say not the easiest job to do but i was able to get it done. Now i have a few basic questions.
Should i clean these parts if so how? 
what kind of cleaner should i use?
also the car has 109,000 miles is it really nessesary to change the timing chain?
how do i know if I have a warped head if i do should i buy a new head? can i buy a new head? where would I buy a new head from? suggestions?
I really like to make sure that when i put the new gasket back everything the leak ceases but i guess there are not real guarantees thats why i like to take a few precatuonary measures before putting everything back.
Any answers to my questions would be really appreciated.


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## IanH (Feb 11, 2003)

check the head for warpage with a straight edge and a feeler gauge.
If you cant do this take it to a machine shop and they can check it for you.

The FSM will say what the max warpage allowed is, normally about 0.004 inches

It also will tell you how much can be removed from the head to give a true surface.


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## IanH (Feb 11, 2003)

In my opinion its not necessary to change the timing chain, the B14's are good for about 200k miles, and then the tensioner wears out not the chain.
I would expect the B15's to be about the same.
Cleaning...
Head can be VAT cleaned at the machine shop.
If not just carefully scrape the matting surfaces if the head is in Spec.
you can clean with simple spray Oils or a carb cleaner if you wish.


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## IanH (Feb 11, 2003)

The gA16 guys are fitting high grade bolts from
McMaster-Carr
The stock spec with angle wrench, but equal to about 46 ft lbs, they are doing these up to 50 ft lbs
With the new high grade Alan head bolts ( use harden washers under the bolt head) 
Torque is then 70 ft lbs ( 10 mm dia)
measure your bolt dia and pitch, and lengths.


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## IanH (Feb 11, 2003)

you can search for rallybob
here is a quote
" ordered from Mcmaster-Carr. 10 mm diameter socket head cap screws, 80 mm long and 100 mm long. For some reason it doesn't mention the thread pitch on the boxes. Grade 12.9. "


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## miguel83 (Oct 13, 2009)

IanH said:


> The gA16 guys are fitting high grade bolts from
> McMaster-Carr
> The stock spec with angle wrench, but equal to about 46 ft lbs, they are doing these up to 50 ft lbs
> With the new high grade Alan head bolts ( use harden washers under the bolt head)
> ...


hey IAN thanks for the reply just really quick let me make sure i understand you. do you think i should buy these new head bolts and torque them to about 50 ftlbs these are obviously better bolts. and secondly another easy question for you do you think the head could be cracked? do i have to remove valves and valve springs to make sure that it is ok? again thanks a bundle for taking the time to respond to my question.


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## IanH (Feb 11, 2003)

Check the head for flatness, get that number then check against the spec.

If its Ok then you dont have to remove the valves. should you ? 
Depends on how long you will keep the car and how bad any build up is on the back of the valves. These cars dont seem to suffer from the same valve to head problems of yesteryear.

You can take it to a Auto machine shop, they will check it for you.

If it has to be machined then you can get them to take the valve out do a valve job, machine the head and re-assemble.

I dont know about now but the last one I did, daughters Tercel, the prices were very reasonable.
before you even start ask price for the valve job, they will give you a fixed price plus any part needed. 
If you go this way buy a complete head set and give them the valve seals.

call up a couple of local auto machine shops, or ask one of you local repair shops who they use


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## IanH (Feb 11, 2003)

head gasket problems on stock engines generally are either the result of overheat or a design weakness

so you see far more failure of the QG than the GA engine even though the GA's are much older.

Rallybob has a very modified GA and excellent knowledge so yes I think this is the way to go for the QG.

The turbo guys regularly use ARP or similar aftermarket head bolts or stud conversions as the heads lift under high boost, so they clamp them down with more force ie torque.

These bolts are also re-usable, where as a lot of factory stretch bolts are replace every use. you need to check the FSM.
the standard Allen bolts are also cheaper !!

If you haven't got the Nissan FSM yet you can download it for free, i can send you a link.

Concerns ?
You may be the first on a QG, and you need to check clearance between the head bolts and anything that moves or bolts down.


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## miguel83 (Oct 13, 2009)

IanH said:


> head gasket problems on stock engines generally are either the result of overheat or a design weakness
> 
> so you see far more failure of the QG than the GA engine even though the GA's are much older.
> 
> ...


IAN i do have the FSm manual thanks all your suggestions thus far. One more question given that i have the head off i also have a horrible squaling noise coming from what i think is the Power steering pump. It squeals something aweful. I have tried tightened to spec and checking flex on the belt over and over again but no cigar. Would you suggest i change the entire power steering pump with pullie? or just the pullie?


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## miguel83 (Oct 13, 2009)

IanH said:


> head gasket problems on stock engines generally are either the result of overheat or a design weakness
> 
> so you see far more failure of the QG than the GA engine even though the GA's are much older.
> 
> ...


sorry for my ignorance what does QG stand for and GA? is this like the type of vehicle mine is a GXE sorry if this is a stupid question I'm just not to familiar with certain terms.
As always you been a hell of a support on this and I appreciate every tip you have given me so far.


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## IanH (Feb 11, 2003)

miguel83 said:


> sorry for my ignorance what does QG stand for and GA? is this like the type of vehicle mine is a GXE sorry if this is a stupid question I'm just not to familiar with certain terms.
> As always you been a hell of a support on this and I appreciate every tip you have given me so far.


The GA series of engine was used from around 1991 I think to 1999 in the USA,
The GA16DE being the later series and used in the USA.

The QG engine series 1.8 Liter in USA, was used from 2000 to 2006 approx.
Rest of the world use same engines and other variants such as GA14DE GA15DE
There is also a QG16DE and maybe others.


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## IanH (Feb 11, 2003)

miguel83 said:


> IAN i do have the FSm manual thanks all your suggestions thus far. One more question given that i have the head off i also have a horrible squaling noise coming from what i think is the Power steering pump. It squeals something aweful. I have tried tightened to spec and checking flex on the belt over and over again but no cigar. Would you suggest i change the entire power steering pump with pullie? or just the pullie?


I don't know the problem, please explain more when it makes niose and what iit sounds like.
but I can tell you if its when you start up, it squeals, then that's the belt and belt tightness on my car.


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## murphywd (Nov 9, 2009)

IanH, I'm having same problem. Can you post/send the FSM link?
thx


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## IanH (Feb 11, 2003)

murphywd said:


> IanH, I'm having same problem. Can you post/send the FSM link?
> thx


you can find at many places, I used
if link doesnt work type in n i c o c l u b for the ***

http://www.********.com/FSM
www.********.com/FSM/

********.com/FSM/


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## marcus17 (Dec 9, 2009)

Thanks Ian!


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## andreasue (Dec 2, 2010)

I think now a days if you buy a head gasket set, installation will be already included but sometimes dealers offer a very large price. So you will be paying the head gasket set itself plus the labor. Are there any autoparts stores that offer free installation of the head gasket?


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