Is is worth it - head gasket?

[mrdance123]

My dad's 83 T4 has a blown head gasket - most likely.
There was a slow loss of coolant - several hundred miles before losing 2 cups,
before the sudden failure to run smoothly, barely limping on 2 cylinders.

I don't think 2 valves would fail simultaneously, would they?
Cylinders 1 & 2 now have near zero compression, maybe 10.

About 5000 miles ago the compression readings were (1-4) 115, 150, 150, 130
Now 3 and 4 read 120 and 110.

If 3 & 4 are true readings, is that too low to run decently after a new head gasket?
They might go up with a new gasket I don't know 1&2 surely will.
Who has the lowest compression readings on a good running car?

[irowiki]

I'd say do it! If you get the head off and the bores are in bad shape, then you might consider a rebuild at that point.

[atoyta]

About 5000 miles ago the compression readings were (1-4) 115, 150, 150, 130
Now 3 and 4 read 120 and 110.

Even 5000 miles ago the readings were far enough out from each other to point to a problem. You may have more going on than just a head gasket.

[Jonymoto]

Sounds like you have a broken gasket between cyliders 1 & 2. According to the manual minimum is 128psi and the difference between the cylinders should be 14psi or less (usually less than 10%)
Have you tried doing the compression test with a small amount of oil in cyl 3 & 4? If the compression goes up you need new rings or a rebore. If not it could be your valves sticking, valve seals or cylinder head gasket leaking

[Petros]

replacing the head gasket is fairly inexpensive and not too much work compared to other cars. follow my head gasket instructions over in the repair guides section.

Replace all of the exhaust valves while you have the head off (they do not cost much, replace all of the valve seals while you are at it), lap the new valves in and likely that will bring all of the compression back up and even it out. the exhaust valves get heat damaged and pitted, than unevenly seal from one cylinder to the next. it is extremely rare for piston rings to wear unevenly and cause uneven compression readings, it is almost certainly the exhaust valves, and a bad head gasket.

The engine will be good for another 100k reliable miles after that, well worth it. headgasket, valves and seals, pulse cleaning solvent, fine sand paper, etc. will cost you about $50. Even if you have to buy some tools to do it, you still come out way a head cost wise.

It is far easier to replace the head gasket than to swap the whole engine out anyway, and you get something you know will be in good running condition.

[marlinh]

Petros, which brand of exhaust valve do you prefer? Rock Auto has two brands that are quite cheap. DNJ and Enginetech. Any comments? Sealed Power is a brand I have used before. It's a bit more expensive. Which would you recommend?

[Petros]

as I recall they are all similar in quality, I would get the one made in Japan first, and than USA made. No china made parts.

the brand name is not really relevant, they all repackage from vendors, so the country of origin of the part is more important than brand name.

[marlinh]

How do you find where the part is manufactured? I can't find that info.

[Jonymoto]

Normally you can tell from the first 2 or 3 digits on the bar code, unless they are re-packaged in the US in which case they may have US codes, I'm not sure about that.
US & Canada = 00-13
Japan - 93-
China - 690 - 695

[Petros]

usually the online retailers will say country of origin for the parts. sometimes you can look at the picture to look for the "made in.." label.

[marlinh]

I am specifically looking at RockAuto's web site and am not finding that info. There aren't any bar codes, just part numbers, Jonymoto.

[Petros]

last time I was on the rockauto website I recall finding that info. You may have to click the "more info" tab, I seem to recall if it said "imported" or "country of origin" or something similar. I buy from Rockauto a lot, and I always select the made in japan, or made in USA items, even if they cost more. many of the items are private label brands, they are typically from an auto parts store chain, but that is just the box it came in, the listing showed the manufacturer.

There is a funny story about this in fact. My 23 year old daughter has a friend Kyle, a hard working guy who was a diesel mechanic when he was in the Marines. He does some side line auto repair (between his construction related jobs) and my daughter takes her car to him often. My wife and I have both known him for a number of years (along with some of our daughter's other collage friends-all good kids), he is a fairly knowledgeable mechanic and I am happy not to have to service my daughter's car. My wife mentioned to him that I buy a lot of our car parts from Rockauto becasue the prices are lower than we can get locally when she was with my daughter where Kyle came along. Kyle went off on a tirade about the cheap crap that Rockauto sells, and he would never buy anything from Rockauto. He said he only buys from NAPA because NAPA warranties all of their parts and they use the same supplier that the car maker uses, so you get factory quality parts.

So my wife, thinking she had she knew more than I did, proceed to chew me out the next day about buying crappy parts from Rockauto for our cars instead of from NAPA. I told here I get the same factory quality parts from rockauto because they list who the supplier is in their listings, and I would not buy the junk commie made parts from Rockauto. You will get junk from Rockauto if you do not shop carefully, they always have lots of different suppliers listed from the same parts. She insisted of course that Kyle knew more than I did about this (he is 27 years old, I am 30 years older and have been working on cars since I was 15).

I had already ordered a full set of brake parts from Rockauto for the mazda, calipers, master, pads, shoes, wheel cylinders, the whole works, and was waiting for them to arrive. I told her I was not canceling the order, and I will show her when they arrive. Rockauto did list they were "new" (not re-manufactured) and the supplier was in Japan. But the listing did say not how they were packaged, there is usually a disclaimer on the RA website saying they may be packaged differently from the supplier listed.

The parts arrived a few days later, much to my surprise all of the parts were in "NAPA" boxes, the whole order was about $170 less than if I bought them at the local NAPA store (even with my Triple A 10 percent discount). I showed them to my wife, and I said, "see, I got NAPA parts from Rock auto, for a lot less money".

Wives always need proof that their husbands do indeed know what they are talking about, no matter how much knowledge they have. Just be careful you do not rub it in too much.

[marlinh]

I'm sorry, but excuse my ignorance. I chose an exhaust valve from Rock Auto, eg.EM2197. If I click on the blue part number it just lists the application. When I click on the more info, it takes me to the web site of the manufacturer and does not tell me anything about where it was made. What am I missing?

[Petros]

I do not know, perhaps they do not show it for all of their products.

I just bought whatever valves they had instock, so far no issues.

[Jonymoto]

Petros, this is my experience with RA. I ordered 2 engine and 1 transmission mounts for my Tercel 4wd from them this year, because I can't get them here in Oz. The postage to Oz was roughly US$80. The engine mounts were correct, but the transmission mount (Anchor 8377) that I received was different to that shown in their catalog. I think it must've been for a 2wd Tercel, yet their catalog shows the one for the 4wd Tercel. The box it came in was labelled Anchor 8377. Needless to say that to post them back and get a new one would cost a lot more than they are worth.