Backfire and Running rough

[sjhebert40]

I took off one morning and my truck backfired.....07 truck with hemi.......since it is running really rough..........trying to figure if this is just a fuel injector problem........took it to one shop and he said he tried a few things but it would have to be opened up and checked out........he dont do that..........he suggested maybe an injector or valve...........diagnostic says #6 is not getting compression...........please help before I take to shop so I can have an idea...........could it really be a valve??????

[Mopar guy]

Make sure pcv valve and all other hoses that are vacume are still hooked up as well as check intake gaskets and valve cover gaskets. Sometimes they can get blown off when it backfired. Do you have a compression guage? You should check the compression yourself to verify it is low. Check the timing also and make sure all spark plags are getting spark. Run it in the dark to see if any spark plug wires are jumping spark. Any gas in the engine oil? You can smell it on the dipstick. Keep posted.

[Scrapper]

if that had no compression it would be knocking like a B are you sure it said no compression? i can see that it would not have enough but again none at all. you could take that #6 plug out and put your thumb on where the plug go's and turn motor over and see if it blows your thumb back. even if you took number 6 wire off and start it it should run worse if it dose have compression.

[sjhebert40]

I am by far no mechanic, but I am mechanically inclined and used to race cars.......so i do know a little bit..............I brought to shop and he told me he did some checks and said it had no compression. I am going to go back to autozone tomorrow and have diagnostic run again and I can let you know more...........it is not knocking, just running rough..very rough.

[sjhebert40]

Originally Posted by Mopar guy

Make sure pcv valve and all other hoses that are vacume are still hooked up as well as check intake gaskets and valve cover gaskets. Sometimes they can get blown off when it backfired. Do you have a compression guage? You should check the compression yourself to verify it is low. Check the timing also and make sure all spark plags are getting spark. Run it in the dark to see if any spark plug wires are jumping spark. Any gas in the engine oil? You can smell it on the dipstick. Keep posted.

I am by far no mechanic, but I am mechanically inclined and used to race cars.......so i do know a little bit..............I brought to shop and he told me he did some checks and said it had no compression. I am going to go back to autozone tomorrow and have diagnostic run again and I can let you know more...........it is not knocking, just running rough..very rough.

[sjhebert40]

Originally Posted by Scrapper

if that had no compression it would be knocking like a B are you sure it said no compression? i can see that it would not have enough but again none at all. you could take that #6 plug out and put your thumb on where the plug go's and turn motor over and see if it blows your thumb back. even if you took number 6 wire off and start it it should run worse if it dose have compression.

I am by far no mechanic, but I am mechanically inclined and used to race cars.......so i do know a little bit..............I brought to shop and he told me he did some checks and said it had no compression. I am going to go back to autozone tomorrow and have diagnostic run again and I can let you know more...........it is not knocking, just running rough..very rough.

[sjhebert40]

OK..............i took it to another shop and he is telling me the same thing..........no compression # 6.............all hoses are in tack..........he does not take the covers off but is suggesting.....thrown rod? springs? any thoughts...........

[Mopar guy]

Pull valve cover and inspect valve train, then again while cranking. Make sure you disable spark to all plugs so it wont start. After that pull that head off.

[hundahunta]

you have a broken valve spring>>>>>>>>

[sjhebert40]

that is what i thought it was.............is that an expensive fix??????????

Originally Posted by hundahunta

you have a broken valve spring>>>>>>>>

[Mopar guy]

Have you pulled the valve cover yet?

[hundahunta]

20$ probably,...