cold start: 3.2 blows up on cold start?! HELP

[P911S]

Hello.

I went out to start my 1984 Carrera (it was last driven two weeks ago) and it backfired when it was turning over and blew the entire motor. I thought it might have been the starter but I pulled the starter to find that the starter is perfect. The motor still turns, but it makes a very nasty metal-to-metal noise. Please help. The backfire was so violent it shook the whole car. I have never heard of a motor seizing during a cold-start. Please let me know if this has happened to someone else or what you think it could be. THE CAR NEVER STARTED, IT BACKFIRED WHEN IT WAS TURNING OVER. It had oil, oil-pressure, and gas.

Please help!

Thank you

[jlex]

Pull the valve covers and see if there's something weird going on with the valve train while you turn the engine by hand. Almost sounds like a timing chain problem...

[SOAZ]

Oh *****, that sucks. Here's a bump to keep this on the top of the page. I'm curious what could have done it.
Could fuel have leaked into a cylinder and then caused a massive backfire that broke something.

Originally Posted by P911S

Hello.

I went out to start my 1984 Carrera (it was last driven two weeks ago) and it backfired when it was turning over and blew the entire motor. I thought it might have been the starter but I pulled the starter to find that the starter is perfect. The motor still turns, but it makes a very nasty metal-to-metal noise. Please help. The backfire was so violent it shook the whole car. I have never heard of a motor seizing during a cold-start. Please let me know if this has happened to someone else or what you think it could be. THE CAR NEVER STARTED, IT BACKFIRED WHEN IT WAS TURNING OVER. It had oil, oil-pressure, and gas.

Please help!

Thank you

[gomezoneill]

How many miles on the engine? First thing I would do is pull the spark plugs and take a close look at them then do a compression test. Pull valve covers check for broken rockers and drain the oil check the magnets on the drain plugs for metal pieces you can also tear apart the oil filter and look for debris.

[yelcab1]

Stop trying to start it. You are likely looking at an engine rebuild totally. No one will know for sure what caused the backfire until they can strip the engine down and find out what broke. If it were my car, I would pull the engine, and then push the car into a safe place for the winter. Then strip the engine down to its block. You will then know what happened.

[vwsamba]

Yeah this happened to me too, fuel leaked into a cyl, bent the connecting rod. The weirdest sound/feeling ever, the whole car rocked

[Pazuzu]

I'm going to assume that since the OP has 1 post, and joined Pelican about 7 weeks ago rather than today (sign up, post in an emergency), that either (a) he just bought the car, or (b) this is a fake account.

I'm going with (a). It might be hard for us to get enough info, he might not have enough seat time to know what the car's history is, how it ran, sounds it made, etc...

[gamin]

jlex is probably correct. Jumped time.

[P911S]

Originally Posted by vwsamba

Yeah this happened to me too, fuel leaked into a cyl, bent the connecting rod. The weirdest sound/feeling ever, the whole car rocked

Unfortunately I think that is what happened. It is very unfortunate because I just bought the Carrera a little over a month ago. I am going to start with the valve covers but I have a feeling it is something more major like a bent rod. Thank you for the advice, I will post pictures later down the road when I get the motor out and taken apart. It will be interesting to see exactly what happened.

[stlrj]

Originally Posted by P911S

Unfortunately I think that is what happened. It is very unfortunate because I just bought the Carrera a little over a month ago. I am going to start with the valve covers but I have a feeling it is something more major like a bent rod. Thank you for the advice, I will post pictures later down the road when I get the motor out and taken apart. It will be interesting to see exactly what happened.

It would be interesting to see if your engine truly is a 3.2 or turns out to be, in actuality, a late 83 SC with CIS. I never heard of a Carrera motor blowing up on startup. CIS engines, on the other hand, do that on a regular basis due to cold start valve issues and Carreras don't since they don't have a cold start valve.

Might want to post some pictures to verify what we're dealing with. Hate to make too many assumptions based on mistaken identity and information.


Cheers,

Joe

[db_cooper]

stlrj makes a good point..could be a CIS car with a blown air box...very common and exciting event. No engine damage usually.

[john walker's workshop]

Airbox blow wouldn't be accompanied by a metal clanking noise.

[jlex]

Originally Posted by john walker's workshop

Airbox blow wouldn't be accompanied by a metal clanking noise.

Certainly in the meantime I'd quit cranking it (wouldn't do a compression test).
Chains can cause lots of racket. Best of luck on the outcome.

[VFR750]

The probable causes are unfortunately quite serious. Metal noises are never good.

There are a few big things that can break. Most will leave evidence.

Don't try to turn it over any more. If there are broken bits in the oil that make it past the filter you will just damage more stuff and pump it into the bearing journals.

Look under the car. Look for any evidence of a new leak. Sadly, look for a hole. You may have thrown a rod.

As others have said pull the spark plugs. With a bright led light and a mirror, you should be able to look into the hole and see a portion of the piston.

Of course any damage to the spark plug itself is a indicator of a major problem.

Some have bought a 10mm borescope. Maybe you can borrow one from a napa or advanced auto (any auto parts store) that would let you look deep into the cylinder, through the spark plug hole.

You might also be able to use the light in the crankcase oil drain hole to see inside.