I replaced the plugs in my 95 geo metro with the NGK $1.99 each brand which is what the manual recommends. The old plugs hadn't been changed in about 6-7 years, and they looked ok, just kinda brown colored at the electrodes.

I was just worried I was going to strip the plug threads, but somehow didn't, just screwed them in by hand until they got tight then gave them one final tightening with the wrench. Did the job in the parking lot outside of the auto parts store. haha.

The car runs great, probably just about as well as it did before.

have a great weekend

You got lucky. How long do you live from the autoparts store? Any time you replace plugs an an aluminum head you need to wait until the engine has cooled down.

do you think i did any damage?

everything seems ok

i live about 20 mins away

maybe i will see if they need to be retightened

You may be fine. My first car was a 92 geo metro. And I didn't know any better and changed plugs after getting back with the new plugs. I didn't notice anything wrong but going down the road later one of the plugs popped out while I was driving. I took it to a shop after that and that was the first thing I was told, never change plugs on an aluminum head until the engine has had time to cool.

I never had an issue changing plugs on an aluminum head warm. As a matter of a fact, the Ford 5.4L Triton 3 Valve engine requires the plugs to be removed with the engine still hot or you will break them. Trust me! I have extracted 19 broken plugs from 11 2004-2006 Ford F-150 & F-250 models with this engine.

Aluminum actually disperses heat better than iron.

I never had an issue changing plugs on an aluminum head warm. As a matter of a fact, the Ford 5.4L Triton 3 Valve engine requires the plugs to be removed with the engine still hot or you will break them. Trust me! I have extracted 19 broken plugs from 11 2004-2006 Ford F-150 & F-250 models with this engine.

Aluminum actually disperses heat better than iron.


Yeah, I bet because the 11 people that had these vehicles tried changing them when hot and overtightened them the first time.

Here are just a few sources that you can look at.
http://www.autotap.com/articles/Spark_Plugs_for_the_Home_Mechanic.html
http://www.aa1car.com/library/sprkplg2.htm
http://www.babcox.com/editorial/us/us110020.htm
http://www.valvoline.com/carcare/articleviewer.asp?pg=ccr20011001sp&cccid=2&scccid=1
http://dodgeram.info/Engine-Gas/SparkPlugs/spkplghnbook.html#tips

I'd love to see proof that Ford recommends pulling out plugs when engine is warm on on engines with aluminum heads. I won't hold my breath till that happens and I certainly wouldn't take any of my vehicles to this guy needing a tune-up.

Yeah, I bet because the 11 people that had these vehicles tried changing them when hot and overtightened them the first time.


Factory original plugs on all of them and in for missfire or 100,000 mile service. I don't need to find documentation. Simply do a search and you will find all the people have problems with the 3 valve 5.4L

Factory original plugs on all of them and in for missfire or 100,000 mile service. I don't need to find documentation. Simply do a search and you will find all the people have problems with the 3 valve 5.4L

Ok, so factory plugs, in for missfire, or in for service, so I guess meaning they brought to you, that means you are the one who broke them?

Apparently, you have no clue. I would not want to create an argument about the Ford Triton 3 Valve spark plugs with you because I know I am correct and have been doing this for years. I will get you documentation later tonight.

The issue you were talking about applies as you say to the 5.4 liter 3 valve triton.

This guy probably took his ford in to see you.
http://www.fordf150.net/forums/viewtopic.php?t=40735

Jk, yes there was a problem with these engines. they had plugs blowing out and people got there plugs broke off when taking in for routine maintenance. In my opinion it's because these people wouldn't treat a vehicle as if there own anyway. I always work on my own.

The problem however has nothing to do with changing the plugs engine warm or cool, the problem is FORD. And those particular heads. They tried to make a 3 valve head bout the same weight and size as the 2 valve. The threaded area where the plugs go in weren't deep enough because of this.

If you are a good mechanic you know when to stop when trying to pull out plugs, you pretty much know your own strength and know when enough is enough, then it's time to turn it the other way a little, back and forth back and forth, taking your time and having alot of patience, keeping the socket down on the plug as perfectly straight as you can. Also being a good mechanic is to just know when to tell the customer I'm sorry but I can't get the job done and reporting the problem to ford instead of knowingly applying too much pressure and breaking spark plugs. Then the customer can contact ford and tell them you warned them the plugs may break when taking them out and they need a signed letter saying they will cover it if it does instead of being left with a vehicle they can't drive and a huge estimate to fix, that the dealership claims they aren't responsible, and ford says they aren't responsible. Being aluminum heads if you try to remove them when hot being just like any other aluminum head, you may be able to get them out because the head is hotter and heat causes expansion, but you still risk damage to you threads.

But yes you are correct about the problem with those particular heads from ford but has nothing to do with giving advice on pulling plugs on aluminum heads.

Well, normally, I extract plugs when cold except on these particular vehicles. 2 of the customers brought them in when they attempted to remove plugs and broke them, so they towed it to me because I have the tools and the know-how to extract broken plugs.

With all respect, let's keep it Geo Metro here.
I'll bet the Ford Triton owners would find this interesting in their threads.

Hey now....watch what you say about Fords. I happen to own a 39 year old Ford truck that still runs good and it has half as much rust as steel left in it. :D