# Intake gasket leak



## 2000SE (Oct 28, 2002)

Why was the thread closed?

The thread stayed on topic and there were no issues besides YOU disagreeing.
We're trying to figure out why the problem exists and to make Nissan do something about it. This is how things get done in this country and why TSB, recalls, and extended warranties come about. 
At the other altimas forum, there's got to be over 50 people who had the problem, and God only knows how many p0300-p0304 error codes, which were initially improperly debugged, that seem to occur with the leak.


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## Asleep (Jan 19, 2003)

i will close this thread and delete it unless you make it for a specific topic. attacking me will get you nowhere. i fully explained why i closed it. be adult and do what i asked.


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## gfriedman (Oct 12, 2005)

AsleepAltima said:


> i will close this thread and delete it unless you make it for a specific topic. attacking me will get you nowhere. i fully explained why i closed it. be adult and do what i asked.



OK Asleep, fair enough. I've spent a lot of time researching this by going through the postings on various forums and googling - and also going through the painful experience of having this defect not covered under warranty (though it should have been) and seeing it up close by doing the repair myself. I think if you had seen the evidence as I have you would agree about this. But that is OK. You have a healthy skepticism so I have to make the case clearer.

There are so many different points that when taken together make the conclusion obvious (to me anyway) that there is an engineering or material defect on the KA24DE in regards to the intake manifold gasket. From reading the posts of dozens of owners it appears it is happening to engines made in the 00-01 timeframe. You don't see posts about this on engines before or after that period. Isn't that odd? If this were just some random problem then you would expect to see about the same number of posts on P0304 and gasket leaks for ANY year car. But that is not the case. Just about all the posts concern specifically 00-01. What we cannot tell from the posts is whether this spike for 00-01 only concerns the California engine. Of the 2 guys that checked (myself included) - both were the Cali model. I'm trying to get in touch with the other guys that posted on this to ask what model they have - but almost all of them are not regulars here and have disabled the direct email option. If you could help me get in contact with them by email it would be appreciated.

What we do know is that Nissan redesigned and changed parts suppliers for the KA24 in September of 99 (the beginning of the '00 model year). Again the same time this problem starts showing up in greater numbers as documented in the posts.

The first hand evidence I had is when I took off my intake manifold and checked the condition of the gasket. The side with the leak was at cylinder 4. When I took off the gasket, the material at the cylinder 4 side was what I can only describe as "baked". It was hard and brittle and would just crack or snap very easily. The closer the gasket was to the number 1 cylinder it remained more pliable and would have more flex instead of just cracking like hard plastic. Obviously the gasket seems to hold up better closer to cylinder 1 because it is cooler there - that is where the passage for the coolant is. It's easy to understand how the gasket material will crack after being subjected to lots of heat (at cyl 4) and engine vibration over the years.

You asked for statistics to back this up. Well if you look at the posts - just about all of them say this problem causes a P0304 code to get thrown. That is a misfire at cylinder 4. Again, if this were some random problem - couldn't we reasonbly expect a normal distribution of the cylinder misfire code from P0301, 302, 303, and 304? But that is not the case. I don't think I have seen any posts on anything other than P0304. Which combined with what I saw firsthand leads to the conclusion that either there is extra heat around cylinder 4 above what the gasket material is rated for - which is an engine design issue. Or the gasket supplier used inferior material that did not conform to the Nissan spec for this part.

Assuming we give Nissan and their suppliers the benefit of the doubt that they consciously didn't want to put inferior materials in the car (which is what I believe), the most logical explanation is that the gasket is being exposed to more heat than it was designed to withstand. The fact that of the 2 cars verified so far happen to be California emission vehicles it seems plausible to me that the extra heat is related to the emission control devices these cars have - specifically the extra cat converter. You have to agree that there is more exhaust backpressure from the extra cat especially as it ages and tends to get blocked. This backpressure makes the engine work harder and get hotter. 

I'd love to know what changed in 02 to eliminate this problem. Was it an engine redesign or different gasket material. I am not familiar with the '02 KA24s but I would assume they were redesigned for 3rd gen.

So that's my case. I wish I would have saved the old gasket so I could post a picture of it and you could see the shiny baked side as opposed to the duller normal looking side that comes from the heat differential on the engine. But it was so brittle it just snapped into little pieces very easily.

I hope this helps clarify the issue. Again, the smoking gun is contained mostly in the posts of guys talking about the P0304 code and how to fix it on the various Nissan bulletin boards on the net. I don't think it's necessary for me to copy and paste them all here - it's easy enough to do a search and read for yourselves.

Gene


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## LONDONDERRY (May 19, 2004)

Just to put my 2 cents in on this issue. Short of doing an engineering study, with fluid dynamics, heat transfer and materials properties of the engine There is a lot of assumptions about gasket failure you are mentioning. For instance, if the gasket is between an cast iron block and aluminum head the thermal expansion rate is different for both materials, this leads to gasket failure.


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## gfriedman (Oct 12, 2005)

LONDONDERRY said:


> Just to put my 2 cents in on this issue. Short of doing an engineering study, with fluid dynamics, heat transfer and materials properties of the engine There is a lot of assumptions about gasket failure you are mentioning. For instance, if the gasket is between an cast iron block and aluminum head the thermal expansion rate is different for both materials, this leads to gasket failure.



True. I'm not sure what material the intake manifold is. I thought is was aluminum.


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## BORNGEARHEAD (Apr 30, 2002)

Nice work. Good stuff. I don't think that this problem is only with the 00-01 ka engines though. I have done numerous intake gaskets on 93-01 Altimas. I don't think that the older Altimas had cyl. specific misfire codes though. I can't remember off-hand. That would be why you don't see that code on the older models. Most of the intake gaskets I have done on the first gen. Altys, they didn't have a check engine light but had a "runs rough at idle" complaint. But those also had a tendency to leak around cyl. 4.

I have not paid attention to whether they were Cal. or Fed. emissions but if you have noticed more with the Cal. emission models, maybe it has to do with their ecm program for the emissions(leaner causing more heat?), i.d.k. Maybe cyl.4 runs leaner than the rest because of component location(egr. etc.).

Your not going to see any 02-up ones because 02 was the redesign year for the Altima which looks like the current new model. Those have completely new powerplants being the 2.5 and 3.5 liter engines.

The gasket is made of(brainfart?) like a Felpro type material. You mnetioned a possible material problem. it could make perfect sense if it is a 00-01 problem. Remember Nissan started having financial problems from 1998-01/02 time. Maybe they cut costs on materials to save money.

I do have a trick to replacing these gaskets that is a much quicker procedure than the manuals show. If you've had the manifold apart/off, you can see that the 2 bottom outside fasteners are studs coming out of the head. These studs are so long that you would have to damn near remove the whole manifold so that the gasket would clear these studs to fit it on. What I do is remove what I need to just be able to slide the manifold away from the head about 1/2"-1". It's just enough to get your fingers in there and get the gasket out and be able to get a razorblade style gasket scraper in there to clean the surfaces. Then I take a razor blade and slot the bottom of the 2 stud holes of the gasket. That way, I just slide the gasket down and it will sit on the studs.


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## BORNGEARHEAD (Apr 30, 2002)

Another thing to take into consideration is how often do intake manifold gaskets leak on ka24de engines on the 240SXs? Up here in the frozen tundra, Nissan did not sell as many of the rear wheel drive cars so we don't see as many of them. This could break it down to materials, manifold configuration, etc.


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## KA24Tech (Feb 2, 2004)

Interesting thread, I am wondering if the EGR tube passing under that side of the intake has a part in cooking the gasket too.

Troy


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## gfriedman (Oct 12, 2005)

Hmm, hadn't thought about that but it makes sense. In fact there is an aluminum bracket on the EGR pipe that bolts right into the head by cyl #4 right next to the throttle linkage. There's gotta be alot of heat transfer going on right there.


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## KA24Tech (Feb 2, 2004)

I started to think about it after I read the posts and after replying to your PM... The 240s and pickups don't have the same frequency of reported problems with the intake gasket and by concidence they don't have the EGR valve or pipe in the same location either (it is on the end of the manifold). Maybe we can come up with something to isolate that tube from the manifold bracket so it separates/isolates the two parts but still supports the tube.

Troy


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## KA24Tech (Feb 2, 2004)

I am not sure how big of a percentage of the leaks occur at number four but I think it is a healthy percentage.
Anyone else have anymore thoughts to contribute?

Troy


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## LONDONDERRY (May 19, 2004)

KA24Tech said:


> I am not sure how big of a percentage of the leaks occur at number four but I think it is a healthy percentage.
> Anyone else have anymore thoughts to contribute?
> 
> Troy


All- 
I have a few questions on the gasket:
what is the material
what is the material thickness
what it the bolt hole spacing and number of bolts on the gasket.
what is the size and length of the bolts
what is the metal that the gasket is sealing?
How hot does the EGR pipe get?

I'm thinking that the reason the gaskets are blowing is a combination of issues. But I'm requesting some more information to do preliminary study. Sorry if this request is a bit much. In the meantime I'll crack open some of my engineering books.

Regards
Frank


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## gfriedman (Oct 12, 2005)

LONDONDERRY said:


> For instance, if the gasket is between an cast iron block and aluminum head the thermal expansion rate is different for both materials, this leads to gasket failure.


Yes, however I'm pretty sure the cylinder head and intake manifold are both aluminum. Even so, the expansion rate would be the same for all cylinders and we could then expect expansion failures anywhere on the gasket. But this problem occurs on cylinder 4 almost exclusively. Why? OK if there is more heat there (and there is) then there will be even more expansion. It's likely a factor but from what I've seen the gasket material loses it's flexibility under very high heat. It becomes hard with no flex at all. So if there is more expansion from heat the gasket will not have any "give" near cyl 4 and just crack. 

I'll try to get some of the info you asked for. Don't know exactly what the gasket is made of. Looks like some kind of synthetic material. But when it comes from the parts store it is very flexible. You can bend it alot without it breaking. Once it sits on the KA24 for any length of time and bakes this totally changes to where it just snaps if you bend it even a little.


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## gfriedman (Oct 12, 2005)

LONDONDERRY said:


> All-
> I have a few questions on the gasket:
> what is the material
> what is the material thickness
> ...


what is the material - looks like some kind of treated paper 
what is the material thickness - 1 mm
what it the bolt hole spacing and number of bolts on the gasket. - there is a picture of it in the Haynes manual upper right corner of page 2A-7
what is the size and length of the bolts - 35 mm x 8 mm
what is the metal that the gasket is sealing? - aluminum to aluminum
How hot does the EGR pipe get? - ??? dont know exactly but it's got to be close to whatever the exhaust manifold is at.


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## annesjn (Dec 2, 2004)

*Removing the intake manifold*

Does anyone have a suggestion on the best way to remove the bolts on the intake manifold? I have all off but one and I cant figure how to get to this one. I can see the bolt through a gap but I can't get a wrench to turn it.

This is a 96 Altima.

Any help please. Thanks!


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## gfriedman (Oct 12, 2005)

I assume you are talking about the lower bolt second one in from the right. The only way I could get to it was to take off the IAC/AAC valve that sits at the end of the manifold/collector. Then you can get to it pretty easy from on top of the car. Caveat is you will need a new IAC gasket as they tear when the valve come off. Other than that some guys say if they jack up the engine a bit it gives better clearance to reach it.

Good luck man...


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## Asleep (Jan 19, 2003)

gfriedman said:


> I assume you are talking about the lower bolt second one in from the right. The only way I could get to it was to take off the IAC/AAC valve that sits at the end of the manifold/collector. Then you can get to it pretty easy from on top of the car. Caveat is you will need a new IAC gasket as they tear when the valve come off. Other than that some guys say if they jack up the engine a bit it gives better clearance to reach it.
> 
> Good luck man...


i think i got that one off with a 1/4 inch drive ratchet and a 12" long extension if i remember correctly.


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## sanjayv (Feb 10, 2006)

Great post, I had undergone the same problem recently and came across this post while researching regarding the issue on google.
First of all, I want to clarify that it is not only Calif cars that are facing this problem, I bought the car from Mossy Nissan in Houston TX and I had the exact same problem. Had to pay around 650 dollars to get the gasket replaced (if only i had know this forum existed before).
Anyway, the next thing is the theory for cylinder 4 is sounding almost perfect to me because it was the same cylin which had misfire with the code P0304.
I totally favor the fact that it should be a recall from Nissan and if there enough people with the same issue, we could file a claim to Nissan requesting for a refund. Let me know if anyone wants to come forward and take further action on this,

-sanjay.


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## gfriedman (Oct 12, 2005)

Sanjay, first off even if you bought your car in TX it could still be a LEV model. If you provide the VIN I can check it or else you can tell from the last 3 letters of the transaxle code which is on the door pillar.

I have called and written letters to Nissan and local and federal authorities on this issue. If you have some better way to approach this I will certainly help.

Gene


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## adonisCrazy (Feb 25, 2005)

I had the same problem last year with my 96 Altima. Had to spend about 600 bucks to get it serviced and was without a car for almost a week. Seems like a definite problem with Altimas that starts with misfire code and a rough idle. With no clear indication of whats the problems, it leads a series of test and wastage of time before one figures out about the intake manifold gasket.


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## gfriedman (Oct 12, 2005)

Actually once I realized I had a leak I could listen closely and hear the hissing sound the leak makes. Sounds like a tire puncture air leak but you have to listen closely over the engine noise. I replaced the gasket a year ago and its holding up well so far but its only been about 15K miles.


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