Did Chrysler fix the notorious 420a headgasket leak?

[RallyEclipse98]

I have always known that a 420a head gasket to typically only last about 100,000 miles before needing to be changed. I have found this to be true. But I ran across this information: Chrysler 1.8, 2.0 & 2.4 engine - Wikipedia, the free encyclopedia (Search for "1998")

According to that page, in 1998 Chrysler fixed the HG issue. Is this true? If I buy a '98 or '99 Eclipse do I not need to worry about premature HG failure?

 

[turboglenn]

Yes, at some point they suposedly finished boring and threading that hole to the proper depth but the really easy cure was to run an extra washer under the bolt or grinda few threads of the bolt on that corner and re-chase the threads with the right die , it wasn't so much a problem ith hardware just a bolt that bottomed out and torqued before properly clamping the head down

 

[RallyEclipse98]

Thanks, Glenn!

 

[Lou98GSX]

chrysler went to a metal head gasket and that fixed the problem . i changed many of them

 

[turboglenn]

chrysler went to a metal head gasket and that fixed the problem . i changed many of them

yea,that was the "user or dealer fix' but i heard they actually solved the problem on the block like i mentioned or just used shorter bolts, I have no proof of either but just what's been told to me.. I solved many of them with either the metal gasket or with the washer or shortening the bolt as mentioned (my ex owned 2 neons while we were together) and had friends with them too... they are the one car i hate to do a timing belt on more than a DSM as far as 4 cylinders go, there's just NO ROOM to work in there, makes me agro

 

[TheRock0720]

Chrysler did NOT fix the issue on all the 420a eclipses/talons I've seen (1995 to 1999), including my very own '99 RS.

They switched up the headgasket, but the main problem lied upon the drivers side rear head bolt bottoming out before it could be torqued to proper spec - due to the hole being too shallow. This being said, the head bolt would loosen up and cause the headgasket to fail in that area (usually around 80,000 miles with the ones I've seen - give or take a few thousand miles). My fix that I've came across when fixing the blown headgasket is to get one of the updated ones and also cut the drivers rear head bolt down a few threads (I did 3 or 4 I believe). Then torqued all them down to spec in order and problem is solved .

Cheers.

Edit- I can see turboglenn beat me to it! I have to agree with what he said about doing the timing on these cars - they SUCK! Chrysler/Mitsubishi always trying to make our lives.... harder .

 

[velocitytuner]

just got my 99 rs out of the shop today...i have hg failure....do you guys know which bolt it is that is bottoming out? both my hg an cam seals are failing..

 

[TheRock0720]

just got my 99 rs out of the shop today...i have hg failure....do you guys know which bolt it is that is bottoming out? both my hg an cam seals are failing..

Yes, it's the head bolt on the drivers side which is furthest to the rear side of the head/block (near the stock battery location).

Cheers.

 

[velocitytuner]

perfect, by chance would it be worth pulling an putting in just a new head bolt shaving the threads down? or should i remove an resurface the whole head?

 

[TheRock0720]

perfect, by chance would it be worth pulling an putting in just a new head bolt shaving the threads down? or should i remove an resurface the whole head?

It's hard to say because I can't see the head. I personally sent off my head to a machine shop so they could install new valve stem seals and I just had them clean and resurface the head since they already had it. And I bought all new head bolts and cut off about 2 threads on all of them and then I cut down 4 on the one that has the problems. I also bought all new gaskets and hoses since some were nearing the end of their brittle lives.

Be sure to install the cam seals properly as I made a silly mistake and they popped out and I had to take it all apart again and replace them. Also I would do the timing components if it hasn't been done recently. You'll be taking it all off anyways, so why not? Better safe than sorry I always say.

Cheers.

 

[Lou98GSX]

you also have to spray the head gasket with a sealer and follow the right torque sequence . all the ones i did never came back . for added insurance change your head bolts

 

[TheRock0720]

you also have to spray the head gasket with a sealer and follow the right torque sequence . all the ones i did never came back . for added insurance change your head bolts

The head gasket I used it specifically said not to use any sealers or copper sprays. I got mine from Rock Auto (the upper gasket kit).

So whatever gasket you choose to use, be sure to read and see if you're supposed to use any sealer or not. But yes, you need to replace the head bolts. They are Torque to Yield, so once they're used once they cannot be used again. I certainly wouldn't advise it...

Cheers.

 

[velocitytuner]

ok didnt think to shave off all the bolts by 2 but that makes sense. by chance is their any pics or diagrams of this work being done for a little more reinsurance. im not very mechanicly inclined but i pick up on stuff quick

 

[TheRock0720]

ok didnt think to shave off all the bolts by 2 but that makes sense. by chance is their any pics or diagrams of this work being done for a little more reinsurance. im not very mechanicly inclined but i pick up on stuff quick

I'm on my phone at the moment, but if you look through my threads posted you'll see I posted some pictures and questions when I did it back in February. Do a quick Google search of "420a head gasket replacement" and you should pull up a plentiful amount of websites about it. If you send me a PM to remind me I'll send you some links later tonight or tomorrow.

Cheers.

 

[velocitytuner]

awesome thanks

 

[Lou98GSX]

the gaskets i used were chrysler ones because i work at a dealership and they have to be sprayed with a sealer . that is what chrysler recommends and for the head bolts i know they are torque to yield but if they didn't stretch you can re use them . you put a straight edge on the bolt to see if its bad

 

[turboglenn]

FOr those lucky enough to catch it before it leaks, I would say it is safe to replace the bolt by removing and either grinding and re-installing or adding a washer, but if it's leaked already i'd say to stay on the safe side and have the gasket replaced and check the head for being out of plane/flatness

Also, I have never used copper spray on a head gasket that lasted (failed for other reasons) but i've never read a manufacturer's statement that advised anything other that to AVOID using things of this nature, aside from some MLS units

I want the copper multi layer crush HG next.. supposedly all the benefits of the MLS without the need to have a superfine RA finish on the head and block, (since i don't want to pull the block just to make sure it's good for the MLS gasket) But i also like that the copper is in the "mid-grounds" of the composite/MLS choice for strength as well because i'd rather have a "safety margin" on the gasket blowing before putting a hole in a piston, or a rod through the block because of det/high cyl pressure/ etc...

perfect, by chance would it be worth pulling an putting in just a new head bolt shaving the threads down? or should i remove an resurface the whole head?

 

[TheFallenJosh]

My 97 RS is at 202,xxx miles never had the HG replaced and its still holding up

 

[velocitytuner]

so i take it the crush hg is better then the modified hg chrysler put out after they realized their stock was garbage?

anyone here have experience mizumo products? head gasket kits an timing kits?

never mind...reviews are not impressive

what would be a decent mid to high end timing kit, water pump all the seals etc....?

 

[glowryder]

Theres a composite, and a MLS. MLS is what you need to use.
Super fine Finish? You mean your to lazy to do it right? Not surprised your having issues...The block RARELY has to be decked. Its the head that is more malleable thus needs decked or at least checked..It takes alot to Fudge up a blocks deck..

Always replace your TTY head bolts.. Theres no way for you to tell they are not stretched without a butt load of fancy Precise tools that you frankly dont have.. Ether get new , or get ARP head studs.

For a FACT, they did fix it in late 97.. as well as MLS.. So if your blowing them on 97+ cars, its probably not due to the TSB on the HG, usually installer error. Alot of mis -info above... Ive copper sprayed my boosted builds, as well as many others, its really the way to go.. Most Pro machine shops will tell you the same.

Do the mechanical timing swap. Its very nice and far more reliable. you can get kits with a nice gates belt to. Get OEM oil and water pumps. Use OEM gaskets where possible.

 

[velocitytuner]

Theres a composite, and a MLS. MLS is what you need to use.
Super fine Finish? You mean your to lazy to do it right? Not surprised your having issues...The block RARELY has to be decked. Its the head that is more malleable thus needs decked or at least checked..It takes alot to Fudge up a blocks deck..

Always replace your TTY head bolts.. Theres no way for you to tell they are not stretched without a butt load of fancy Precise tools that you frankly dont have.. Ether get new , or get ARP head studs.

For a FACT, they did fix it in late 97.. as well as MLS.. So if your blowing them on 97+ cars, its probably not due to the TSB on the HG, usually installer error. Alot of mis -info above... Ive copper sprayed my boosted builds, as well as many others, its really the way to go.. Most Pro machine shops will tell you the same.

Do the mechanical timing swap. Its very nice and far more reliable. you can get kits with a nice gates belt to. Get OEM oil and water pumps. Use OEM gaskets where possible.

not sure if ## refering to me as lazy but im far from it just not mechanicly inclined like most are here still at a stage im learning like most that are here.

whats the difference between tty an arp? my car is basicly stock besides cool air intake....nothing else has been done to this motor as of yet..

 

[grothe3297venge]

TTY (torque-to-yield) head bolts are basically stock head bolts, whereas ARP are more of a high end grade head bolt to handle anything you throw at it.

ARP head bolts are usually used on boosted builds, but you can use these and be rest assured they will last longer than stock (given you do all regular maintenance)

 

[velocitytuner]

TTY (torque-to-yield) head bolts are basically stock head bolts, whereas ARP are more of a high end grade head bolt to handle anything you throw at it.

ARP head bolts are usually used on boosted builds, but why you can use these and be rest assured they will last longer than stock (given you do all regular maintenance)

would the arp require grinding down such as the stock bolts to prevent the head gasket leaking down the road again?

 

[grothe3297venge]

would the arp require grinding down such as the stock bolts to prevent the head gasket leaking down the road again?

With the information glowryder just stated, and your car being a 99, then no you should not. Just torque in the correct sequence and you should be good!

Just make SURE that you get your head checked and resurfaced if it needs it, and get an OEM MLS head gasket.

 

[velocitytuner]

ok cool just everyone here has an opnion and a different version of what should be done but ill roll with it.
thanks again man