Kia Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
I'm trying to rebuild the engine on a 2000 Sportage. It was my in-laws and it overheated, resulting in a cracked head and blown gasket. I was able to get a reman head and a complete gasket set online. However, head bolts are not available anywhere except for the dealer at $8.05 each. I know they're not Torque to Yield, but opinions seem to be divided in the forums on whether they need to be replaced or not. It would be nice to to have to spend another $85 on bolts if I don't need to. Anyone have any experience or opinion on this? Thanks!

dh
 

·
Registered
Caribou, Otter, Buffalo
Joined
·
2,696 Posts
I have done it both ways, take into consideration the engine did overheat..

Use a good calibrated torque wrench....

.... Philip
 

·
Registered
2013 Sorento LX V6 AWD
Joined
·
1,141 Posts
What's going to happen if you use the old ones? Beings that the engine overheated, the bolt's hardness and strength integrity may have been compromised. Let's say you use them; what if one or more fail and you blow a head gasket again, maybe incurring collateral damage as well. What's it going to cost you to repair it again? Heck, it if blows on the freeway, the tow alone could cost you the 85 bucks, not to mention the inconvenience. What if there's some sort of accident in your family or other loved one and you're taking that someone to the emergency room when it happens to give out? Is that $85 potentially worth someone's life?

Then again, you might drive for years with nary a problem. but . . . is the time, aggravation of doing the same repair job over again and risk of future break-downs worth the $85? In my way of thinking, it's not. Do it right the first time and there shouldn't be a next time. ;)

-----------------------------------

Edit: I don't know where you are, but there's a Mod here, Cobra259 who's real job is in the parts dept. at a KIA dealership, and he has sometimes been able to save members here some money, depending of course where they are in relation to where he is with shipping and all, but you might see if he can save you anything. But really, unless things are really, really tight for you money-wise, $85 is not that bad and is cheap insurance.
 

·
Registered
Joined
·
63 Posts
What's going to happen if you use the old ones? Beings that the engine overheated, the bolt's hardness and strength integrity may have been compromised. Let's say you use them; what if one or more fail and you blow a head gasket again, maybe incurring collateral damage as well. What's it going to cost you to repair it again? Heck, it if blows on the freeway, the tow alone could cost you the 85 bucks, not to mention the inconvenience. What if there's some sort of accident in your family or other loved one and you're taking that someone to the emergency room when it happens to give out? Is that $85 potentially worth someone's life?

Then again, you might drive for years with nary a problem. but . . . is the time, aggravation of doing the same repair job over again and risk of future break-downs worth the $85? In my way of thinking, it's not. Do it right the first time and there shouldn't be a next time. ;)

-----------------------------------

Edit: I don't know where you are, but there's a Mod here, Cobra259 who's real job is in the parts dept. at a KIA dealership, and he has sometimes been able to save members here some money, depending of course where they are in relation to where he is with shipping and all, but you might see if he can save you anything. But really, unless things are really, really tight for you money-wise, $85 is not that bad and is cheap insurance.

The likeliness of failure in new or old, is exactly the same, 6 one half a dozen the other...



Sent from AutoGuide.com Free App.

It's a work in progress, but I'll have the satisfaction that I did the work and a little more knowledge than when I started
 

·
Premium Member
1999 kia Sportage 2.3l long stroke modified ,2005 Magna 3.5l,2006 nissan navara d22
Joined
·
132 Posts
When I had built up my stroked motor I put the same question to my engine re builder whom did the rebore,
Crank grind etc he told me the original kia bolts are not stretch bolts that are now commonly used in all modern engines.Of course aftermarket ones are available but he was not going to guarantee the quality compared to originals.I had rebuilt a couple of engines for my kids cars and was used to factoring in the price of new bolts previously.
Have had no problems with my reused bolts.
Also an engine that has been cooked would reach temperatures slightly above 100 degrees C.Tempering of steel components is done at 100-200 C and cooled slowly. So theoretically all should be good, but it it worth the small expense for piece of mind.
Regards Dave
 

·
Registered
'02 Sportage 2 door.
Joined
·
339 Posts
Just throwing this out there. Since the Sportage engine is a Mazda 626 derivative would head bolts for a 626 work?
 

·
Premium Member
96 4 DOOR 4WD SPORTAGE, 2014 Hyundai Elantra GT, 2015 Accent Hatchback Sport
Joined
·
651 Posts
Kia Sportage Head Bolts are TORQUE TO YIELD bolts.

Here is an explanation of Torque to Yield Bolts:

With a regular head bolt a technician could torque a bolt to its yield point and it would return to its original form and length when removed. This is because of its elasticity, it is able to stretch and then return to its original form.

This is not so with a torque to yield bolt. There are two terms related to this phenomenon. The first is elastic deformation and the second is plastic deformation:

1. Elastic deformation: This is the amount of force or torque where you haven't changed the shape or length of the bolt. At this point you are able to reuse the bolt as it hasn't changed its shape.

2. Plastic deformation: This is the point past elastic deformation where the bolt has changed its shape and length. At this point the bolt can not be reused and needs to be replaced.

For example an aluminum cylinder head will be torqued in a sequence say one to ten. The first pass would be a torque of 36 foot pounds. This is the elastic deformation point. The second pass would be a 90 degree angle or a quarter turn. At this point the bolt is going into plastic deformation. The third pass would be another 90 degree angle. At this point the bolt has changed its form and if loosened or removed it must be replaced with a new torque to yield bolt.

So you can re-use the standard head bolts, but when it comes to torque to yield bolts, if they have reached plastic deformation, they need to be replaced with new ones. Remember, a lightly oiled bolt should be easily screwed all the way in and out of the bore with only your fingertips. If there is excess resistance there is probably something wrong with the bolts threads. Always check with manufacturers specifications and TSB's when working with engine bolts, especially if you suspect them to be TTY bolts. TTY bolts are common and typically used to clamp cylinder heads on late model engines. Be careful, a loss of clamping force will ultimately lead to head gasket failure.


Can you re-use the old bolts--yes with risk.

You should PM COBRA 259 here on the forum and see what he can do for you on a set of head bolts.

Hope this helps.

UPYOURKIA
 

·
Registered
Joined
·
1 Posts
If your torque spec calls for a degree wheel then you have stretch bolts and should not be reused.
 

·
Super Moderator
99 Kia Elan 1.8L, 17 Ford Edge Sport 2.7L V6, 15 Mustang 3.7L V6, 08 Harley Nightrain
Joined
·
10,373 Posts

·
Registered
2019 Kia Sportage. SX with AWD. 2.0L Direct Injected Turbocharged & Intercooled Gas.
Joined
·
481 Posts
For what its worth...I designed cylinder heads and was responsible for the head gasket and bolts as well.
At this american manufacture all the cylinder head bolts for all engines were designed as torque to yield.
Most modern engines using aluminum take the head bolts into yield. Who told you they were not torque to yield? Did you see that in a technical manual?
Don't take a chance of a bolt relaxing and creating a new headache.
Do the job correctly and install new bolts! Don't be penny wise and pound foolish!
 
1 - 14 of 14 Posts
Top