Check Engine On Off On Off - Repeat

jerryperry_182487
Sun, 02 Oct 2022 18:45:19 +0000
Maintenance/Repairs

2000 4Runner V6 Manual 389K Miles - Well Maintained

My 4Runner very suddenly started running rough, then Check Engine started flashing, then solid. Next morning, ran smooth as usual and Check Engine eventually went off on its own. Next day, suddenly rough again, Check Engine on, later smooth, Check Engine off. And repeat almost daily. I’ve gassed up at three different locations just in case. Also added BG44K.

Managed to get codes when Check Engine was still on once - P300, and other PXX codes - cylinder misfires.

My go-to shop replaced spark plugs, wires and coils (they were all overdue anyway). Next day, same problem. An engine compression check showed two cylinders below spec compression. Recommendation - engine rebuild - I laughed at the price.

I understand compression loss - it’s an old truck - but the Check Engine symptom started abruptly and self corrects, and I don’t think the compression issue is suddenly fixing itself, then dropping again. Anyone familiar with this problem?

11 posts - 9 participants