diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 6a8d8ce619..5963900c97 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -23,7 +23,6 @@ import (
 	"math/big"
 	"math/rand"
 	"sync"
-	"sync/atomic"
 	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
@@ -195,9 +194,8 @@ func ecrecover(header *types.Header, sigcache *lru.ARCCache) (common.Address, er
 // Clique is the proof-of-authority consensus engine proposed to support the
 // Ethereum testnet following the Ropsten attacks.
 type Clique struct {
-	config  *params.CliqueConfig // Consensus engine configuration parameters
-	db      ethdb.Database       // Database to store and retrieve snapshot checkpoints
-	running int32                // Indicator whether clique engine is running or not.
+	config *params.CliqueConfig // Consensus engine configuration parameters
+	db     ethdb.Database       // Database to store and retrieve snapshot checkpoints
 
 	recents    *lru.ARCCache // Snapshots for recent block to speed up reorgs
 	signatures *lru.ARCCache // Signatures of recent blocks to speed up mining
@@ -603,10 +601,6 @@ func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-ch
 	if c.config.Period == 0 && len(block.Transactions()) == 0 {
 		return nil, errWaitTransactions
 	}
-	// Make sure clique engine is started.
-	if !c.IsRunning() {
-		return nil, consensus.ErrEngineNotStart
-	}
 	// Don't hold the signer fields for the entire sealing procedure
 	c.lock.RLock()
 	signer, signFn := c.signer, c.signFn
@@ -678,25 +672,6 @@ func CalcDifficulty(snap *Snapshot, signer common.Address) *big.Int {
 	return new(big.Int).Set(diffNoTurn)
 }
 
-// Start implements consensus.Engine, starting the clique consensus engine.
-func (c *Clique) Start() {
-	if atomic.CompareAndSwapInt32(&c.running, 0, 1) {
-		log.Info("Start clique consensus engine")
-	}
-}
-
-// Stop implements consensus.Engine, stopping the clique consensus engine.
-func (c *Clique) Stop() {
-	if atomic.CompareAndSwapInt32(&c.running, 1, 0) {
-		log.Info("Stop clique consensus engine")
-	}
-}
-
-// IsRunning implements consensus.Engine, returning an indication if the clique engine is currently mining.
-func (c *Clique) IsRunning() bool {
-	return atomic.LoadInt32(&c.running) > 0
-}
-
 // Close implements consensus.Engine, returning internal error and close the clique.
 func (c *Clique) Close() error {
 	return nil
diff --git a/consensus/consensus.go b/consensus/consensus.go
index 3562388d51..ae0fefb490 100644
--- a/consensus/consensus.go
+++ b/consensus/consensus.go
@@ -97,15 +97,6 @@ type Engine interface {
 	// APIs returns the RPC APIs this consensus engine provides.
 	APIs(chain ChainReader) []rpc.API
 
-	// Start starts the consensus engine.
-	Start()
-
-	// Stop stops the consensus engine.
-	Stop()
-
-	// IsRunning returns an indication whether consensus engine is running or not.
-	IsRunning() bool
-
 	// Close closes the consensus engine.
 	Close() error
 }
diff --git a/consensus/errors.go b/consensus/errors.go
index c7d7073e19..a005c5f63d 100644
--- a/consensus/errors.go
+++ b/consensus/errors.go
@@ -34,7 +34,4 @@ var (
 	// ErrInvalidNumber is returned if a block's number doesn't equal it's parent's
 	// plus one.
 	ErrInvalidNumber = errors.New("invalid block number")
-
-	// ErrEngineNotStart is returned if the consensus engine is not started.
-	ErrEngineNotStart = errors.New("consensus engine is not started")
 )
diff --git a/consensus/ethash/api.go b/consensus/ethash/api.go
index eae6c169a8..b950fbd92c 100644
--- a/consensus/ethash/api.go
+++ b/consensus/ethash/api.go
@@ -51,12 +51,6 @@ func (api *API) GetWork() ([3]string, error) {
 		err    error
 	)
 
-	// Trigger ethash to start in remote mining mode(local/cpu mining is disabled)
-	// if ethash is not running.
-	if !api.ethash.IsRunning() {
-		api.ethash.StartMining(new(int))
-	}
-
 	select {
 	case api.ethash.fetchWorkCh <- &sealWork{errCh: errCh, resCh: workCh}:
 	case <-api.ethash.exitCh:
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index bee4efe9e6..eb0f73d98b 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"math/big"
 	"runtime"
-	"sync/atomic"
 	"time"
 
 	mapset "github.com/deckarep/golang-set"
@@ -32,7 +31,6 @@ import (
 	"github.com/ethereum/go-ethereum/consensus/misc"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 )
 
@@ -554,22 +552,3 @@ func accumulateRewards(config *params.ChainConfig, state *state.StateDB, header
 	}
 	state.AddBalance(header.Coinbase, reward)
 }
-
-// Start implements consensus.Engine, starting the ethash engine.
-func (ethash *Ethash) Start() {
-	if atomic.CompareAndSwapInt32(&ethash.running, 0, 1) {
-		log.Info("Start ethash consensus engine")
-	}
-}
-
-// Stop implements consensus.Engine, stopping the ethash engine.
-func (ethash *Ethash) Stop() {
-	if atomic.CompareAndSwapInt32(&ethash.running, 1, 0) {
-		log.Info("Stop ethash consensus engine")
-	}
-}
-
-// IsRunning implements consensus.Engine, returning an indication if the ethash engine is currently mining.
-func (ethash *Ethash) IsRunning() bool {
-	return atomic.LoadInt32(&ethash.running) > 0
-}
diff --git a/consensus/ethash/ethash.go b/consensus/ethash/ethash.go
index caf272ab07..3fff266410 100644
--- a/consensus/ethash/ethash.go
+++ b/consensus/ethash/ethash.go
@@ -428,7 +428,6 @@ type Ethash struct {
 	threads  int           // Number of threads to mine on if mining
 	update   chan struct{} // Notification channel to update mining parameters
 	hashrate metrics.Meter // Meter tracking the average hashrate
-	running  int32         // Indicator whether ethash engine is running or not.
 
 	// Remote sealer related fields
 	workCh       chan *types.Block // Notification channel to push new work to remote sealer
@@ -487,7 +486,6 @@ func NewTester() *Ethash {
 		datasets:     newlru("dataset", 1, newDataset),
 		update:       make(chan struct{}),
 		hashrate:     metrics.NewMeter(),
-		running:      1, // enable local mining by default
 		workCh:       make(chan *types.Block),
 		resultCh:     make(chan *types.Block),
 		fetchWorkCh:  make(chan *sealWork),
@@ -680,20 +678,6 @@ func (ethash *Ethash) APIs(chain consensus.ChainReader) []rpc.API {
 	}
 }
 
-// StartMining starts the ethash engine with the given number of threads.
-// If threads is nil the number of workers started is equal to the number of logical CPUs
-// that are usable by this process. If threads is 0, than local/cpu mining will be disabled.
-// If mining is already running, this method adjust the number of threads allowed to use.
-func (ethash *Ethash) StartMining(threads *int) {
-	if threads == nil {
-		threads = new(int)
-	} else if *threads == 0 {
-		*threads = -1 // Disable local/cpu mining.
-	}
-	ethash.Start()
-	ethash.SetThreads(*threads)
-}
-
 // SeedHash is the seed to use for generating a verification cache and the mining
 // dataset.
 func SeedHash(block uint64) []byte {
diff --git a/consensus/ethash/sealer.go b/consensus/ethash/sealer.go
index 4c164b779b..539e783a6c 100644
--- a/consensus/ethash/sealer.go
+++ b/consensus/ethash/sealer.go
@@ -50,10 +50,6 @@ func (ethash *Ethash) Seal(chain consensus.ChainReader, block *types.Block, stop
 	if ethash.shared != nil {
 		return ethash.shared.Seal(chain, block, stop)
 	}
-	// Make sure ethash engine is started.
-	if !ethash.IsRunning() {
-		return nil, consensus.ErrEngineNotStart
-	}
 	// Create a runner and the multiple search threads it directs
 	abort := make(chan struct{})
 
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 0fb5ca52b2..7007f85ddf 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -465,9 +465,6 @@ func (pool *TxPool) SetGasPrice(price *big.Int) {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
 
-	if pool.gasPrice == price {
-		return
-	}
 	pool.gasPrice = price
 	for _, tx := range pool.priced.Cap(price, pool.locals) {
 		pool.removeTx(tx.Hash(), false)
diff --git a/eth/api.go b/eth/api.go
index a6b4319872..c1fbcb6d40 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -112,14 +112,16 @@ func (api *PrivateMinerAPI) Start(threads *int) error {
 		log.Info("Updated mining threads", "threads", *threads)
 		th.SetThreads(*threads)
 	}
-	// Propagate the initial price point to the transaction pool
-	api.e.lock.RLock()
-	price := api.e.gasPrice
-	api.e.lock.RUnlock()
-	api.e.txPool.SetGasPrice(price)
-
 	// Start the miner and return
-	return api.e.StartMining(true)
+	if !api.e.IsMining() {
+		// Propagate the initial price point to the transaction pool
+		api.e.lock.RLock()
+		price := api.e.gasPrice
+		api.e.lock.RUnlock()
+		api.e.txPool.SetGasPrice(price)
+		return api.e.StartMining(true)
+	}
+	return nil
 }
 
 // Stop the miner
diff --git a/eth/backend.go b/eth/backend.go
index a41adebcfd..32946a0ab3 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -167,12 +167,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		return nil, err
 	}
 
-	// Specify etherbase explicitly.
-	var etherbase common.Address
-	if addr, err := eth.Etherbase(); err == nil {
-		etherbase = addr
-	}
-	eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.engine, etherbase)
+	eth.miner = miner.New(eth, eth.chainConfig, eth.EventMux(), eth.engine)
 	eth.miner.SetExtra(makeExtraData(config.ExtraData))
 
 	eth.APIBackend = &EthAPIBackend{eth, nil}
@@ -344,7 +339,7 @@ func (s *Ethereum) StartMining(local bool) error {
 		log.Error("Cannot start mining without etherbase", "err", err)
 		return fmt.Errorf("etherbase missing: %v", err)
 	}
-	if clique, ok := s.engine.(*clique.Clique); ok && !clique.IsRunning() {
+	if clique, ok := s.engine.(*clique.Clique); ok {
 		wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
 		if wallet == nil || err != nil {
 			log.Error("Etherbase account unavailable locally", "err", err)
diff --git a/miner/agent.go b/miner/agent.go
index 8d37921ef5..95d835bd78 100644
--- a/miner/agent.go
+++ b/miner/agent.go
@@ -62,9 +62,7 @@ func (self *CpuAgent) Stop() {
 	if !atomic.CompareAndSwapInt32(&self.started, 1, 0) {
 		return // agent already stopped
 	}
-	// Close the pending routines.
-	close(self.stop)
-
+	self.stop <- struct{}{}
 done:
 	// Empty work channel
 	for {
@@ -105,7 +103,7 @@ func (self *CpuAgent) mine(work *Work, stop <-chan struct{}) {
 		log.Info("Successfully sealed new block", "number", result.Number(), "hash", result.Hash())
 		self.returnCh <- &Result{work, result}
 	} else {
-		if err != nil && err != consensus.ErrEngineNotStart {
+		if err != nil {
 			log.Warn("Block sealing failed", "err", err)
 		}
 		self.returnCh <- nil
diff --git a/miner/miner.go b/miner/miner.go
index 949ce0f2b2..4c5717c8ad 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -54,13 +54,12 @@ type Miner struct {
 	shouldStart int32 // should start indicates whether we should start after sync
 }
 
-func New(eth Backend, config *params.ChainConfig, mux *event.TypeMux, engine consensus.Engine, coinbase common.Address) *Miner {
+func New(eth Backend, config *params.ChainConfig, mux *event.TypeMux, engine consensus.Engine) *Miner {
 	miner := &Miner{
 		eth:      eth,
 		mux:      mux,
 		engine:   engine,
-		coinbase: coinbase,
-		worker:   newWorker(config, engine, coinbase, eth, mux),
+		worker:   newWorker(config, engine, eth, mux),
 		canStart: 1,
 	}
 	miner.Register(NewCpuAgent(eth.BlockChain(), engine))
@@ -110,6 +109,7 @@ func (self *Miner) Start(coinbase common.Address) {
 		return
 	}
 	self.worker.start()
+	self.worker.commitNewWork()
 }
 
 func (self *Miner) Stop() {
@@ -126,7 +126,7 @@ func (self *Miner) Unregister(agent Agent) {
 }
 
 func (self *Miner) Mining() bool {
-	return self.engine.IsRunning()
+	return self.worker.isRunning()
 }
 
 func (self *Miner) HashRate() uint64 {
diff --git a/miner/worker.go b/miner/worker.go
index 1cd666f17c..f1194fa18a 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -126,10 +126,11 @@ type worker struct {
 	unconfirmed *unconfirmedBlocks // set of locally mined blocks pending canonicalness confirmations
 
 	// atomic status counters
-	atWork int32 // The number of in-flight consensus engine work.
+	atWork  int32 // The number of in-flight consensus engine work.
+	running int32 // The indicator whether the consensus engine is running or not.
 }
 
-func newWorker(config *params.ChainConfig, engine consensus.Engine, coinbase common.Address, eth Backend, mux *event.TypeMux) *worker {
+func newWorker(config *params.ChainConfig, engine consensus.Engine, eth Backend, mux *event.TypeMux) *worker {
 	worker := &worker{
 		config:         config,
 		engine:         engine,
@@ -143,7 +144,6 @@ func newWorker(config *params.ChainConfig, engine consensus.Engine, coinbase com
 		chain:          eth.BlockChain(),
 		proc:           eth.BlockChain().Validator(),
 		possibleUncles: make(map[common.Hash]*types.Block),
-		coinbase:       coinbase,
 		agents:         make(map[Agent]struct{}),
 		unconfirmed:    newUnconfirmedBlocks(eth.BlockChain(), miningLogAtDepth),
 	}
@@ -189,8 +189,7 @@ func (self *worker) pendingBlock() *types.Block {
 func (self *worker) start() {
 	self.mu.Lock()
 	defer self.mu.Unlock()
-
-	self.engine.Start()
+	atomic.StoreInt32(&self.running, 1)
 	for agent := range self.agents {
 		agent.Start()
 	}
@@ -200,19 +199,25 @@ func (self *worker) stop() {
 	self.mu.Lock()
 	defer self.mu.Unlock()
 
-	self.engine.Stop()
+	atomic.StoreInt32(&self.running, 0)
 	for agent := range self.agents {
 		agent.Stop()
 	}
 	atomic.StoreInt32(&self.atWork, 0)
 }
 
+func (self *worker) isRunning() bool {
+	return atomic.LoadInt32(&self.running) == 1
+}
+
 func (self *worker) register(agent Agent) {
 	self.mu.Lock()
 	defer self.mu.Unlock()
 	self.agents[agent] = struct{}{}
 	agent.SetReturnCh(self.recv)
-	agent.Start()
+	if self.isRunning() {
+		agent.Start()
+	}
 }
 
 func (self *worker) unregister(agent Agent) {
@@ -227,11 +232,6 @@ func (self *worker) update() {
 	defer self.chainHeadSub.Unsubscribe()
 	defer self.chainSideSub.Unsubscribe()
 
-	ticker := time.NewTicker(500 * time.Millisecond)
-	defer ticker.Stop()
-
-	var started bool // Indication whether consensus engine is started
-
 	for {
 		// A real event arrived, process interesting content
 		select {
@@ -252,7 +252,7 @@ func (self *worker) update() {
 			// Note all transactions received may not be continuous with transactions
 			// already included in the current mining block. These transactions will
 			// be automatically eliminated.
-			if !self.engine.IsRunning() {
+			if !self.isRunning() {
 				self.currentMu.Lock()
 				txs := make(map[common.Address]types.Transactions)
 				for _, tx := range ev.Txs {
@@ -270,17 +270,6 @@ func (self *worker) update() {
 				}
 			}
 
-		// Commit new work when consensus engine is started.
-		case <-ticker.C:
-			if self.engine.IsRunning() {
-				if !started {
-					self.commitNewWork()
-					started = true
-				}
-			} else {
-				started = false
-			}
-
 		// System stopped
 		case <-self.txsSub.Err():
 			return
@@ -340,11 +329,6 @@ func (self *worker) wait() {
 
 // push sends a new work task to currently live miner agents.
 func (self *worker) push(work *Work) {
-	// Never send task to consensus engine if the etherbase is not specified.
-	if self.engine.IsRunning() && work.header.Coinbase == (common.Address{}) {
-		log.Info("Please explicitly specifies the etherbase")
-		return
-	}
 	for agent := range self.agents {
 		atomic.AddInt32(&self.atWork, 1)
 		if ch := agent.Work(); ch != nil {
@@ -416,7 +400,11 @@ func (self *worker) commitNewWork() {
 		Time:       big.NewInt(tstamp),
 	}
 	// Only set the coinbase if our consensus engine is running (avoid spurious block rewards)
-	if self.engine.IsRunning() {
+	if self.isRunning() {
+		if self.coinbase == (common.Address{}) {
+			log.Error("Refusing to mine without etherbase")
+			return
+		}
 		header.Coinbase = self.coinbase
 	}
 	if err := self.engine.Prepare(self.chain, header); err != nil {
@@ -479,10 +467,10 @@ func (self *worker) commitNewWork() {
 		// Push empty work in advance without applying pending transaction.
 		// The reason is transactions execution can cost a lot and sealer need to
 		// take advantage of this part time.
-		if self.engine.IsRunning() {
+		if self.isRunning() {
 			log.Info("Commit new empty mining work", "number", work.Block.Number(), "uncles", len(uncles))
+			self.push(work)
 		}
-		self.push(work)
 	}
 
 	// Fill the block with all available pending transactions.
@@ -500,12 +488,11 @@ func (self *worker) commitNewWork() {
 		return
 	}
 	// We only care about logging if we're actually mining.
-	if self.engine.IsRunning() {
+	if self.isRunning() {
 		log.Info("Commit new full mining work", "number", work.Block.Number(), "txs", work.tcount, "uncles", len(uncles), "elapsed", common.PrettyDuration(time.Since(tstart)))
 		self.unconfirmed.Shift(work.Block.NumberU64() - 1)
+		self.push(work)
 	}
-	// Push full work to sealer, which will replace the empty work sent before automatically.
-	self.push(work)
 	self.updateSnapshot()
 }